Group Title: relationships of the salamanders of the genus Plethodon..
Title: The relationships of the salamanders of the genus Plethodon..
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Title: The relationships of the salamanders of the genus Plethodon..
Physical Description: 214 leaves. : ; 28 cm.
Language: English
Creator: Highton, Richard Taylor, 1927-
Publication Date: 1956
Copyright Date: 1956
 Subjects
Subject: Salamanders   ( lcsh )
Biology thesis Ph. D
Dissertations, Academic -- Biology -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Thesis: Thesis -- University of Florida, 1956.
Bibliography: Bibliography: leaves 198-213.
Additional Physical Form: Also available on World Wide Web
General Note: Manuscript copy.
General Note: Vita.
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Bibliographic ID: UF00098028
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000543150
oclc - 13110546
notis - ACW6856

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THE RELATIONSHIPS OF THE SALAMANDERS

OF THE GENUS PLETHODON










By
RICHARD HIGHTON


A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY











UNIVERSITY OF FLORIDA
June, 1956











TABLE OF CONTENTS


INTRODUCTION . . . . . . . . . .

MiTHODS ..... . ........... .

THE RELATION PETWEEI! NUITIER OF COSTAL GROOVES AND TRUNK
VERTEBPAE I LEODON . . . . . . .

PIGLMITA TION IN THE GENUS PLETHODON . . . ..

KEY TO TIH StAtLUt1DiRS OF THE GEMUS PLTHODON . ..

SYSTE.MTICS . . ... . . . . . . ...

The Western Plethodons ...... . . .


Plethodon vandykei Group . . . .

Plethodon vandykei vandykei Van Denburgh

Plethodon vandykei idahoensis Slater and S

Plathodon vandykei larselli Burns . .

Plethodon vehiculun Group . . . . .

Plethodon dunni Bishop .... . .

Plethodon vehiculum (Cooper) . . .

Plethodon products Group . . . ..

Plethodon products, new name . .

Plethodon neomexicanus Group . . ..

Plethodon neoRexicanus Stebbins and Riemer

The Eastern Small Plethodons . .. .

Plethodon welleri Group ...........

Flethodon welleri Walker . . . .


* pp

Lipp


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9

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Page

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.9 5


8

12

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.. 20

. 29

3L
. 34

35

. 37

37

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. 3
. 41



. 83
43






46
S. 7


51

51


Plethodcn richmrondi richmondi Netting and Miittlean

Plethodon richriondi papei pighton and Grobrian .

Plethodon richrondi netting Green . . .


,-~"


*


*


*









Plethodon cinereus Group .............. 65

Plethodon dorsalis dorsalis Cope . . .. 68

Plethodon dorsalis angusticlavius Grobman . .. 71

Plethodon cinereus cinereus (Green) . . . 76

Plethodon cinereus serratus Grobman . . .. 78

Plethodon cinereus polycentratus Highton and Grobman 79

The Eastern Large Plethodons . . . ..... . 80

Plethodon wehrlei Group ............... 90

Plethodon wehrlei wehrlei Fowler and Dunn . . 93

Plethoden wehrlei dixi Pope and Fowler . .. 96

Plethodon wehrlei jacksoni NeQ . . . . 96

Plethodon yonahlossee Group ........ ... 97

Plethodon yonahlossee Dnn ........... 100

Plethodon ouaehitae Dunn and Heinse . . . 103

Plethodon caddoensis Pope and Pope . . . 105

P1ethodon glutinosus Group . .......... 106

Plethodon jordani jordani Blatchley . . . 129

Plethodon jordani metcalfi Brimley . . . 132

Plethodon jordani shermani Stejneger . . . 134

Plethodon jordani unicoi, new subspecies . . 135

Plethodon jordani melaventris Pope and Hairston 136

Plethodon jordani rabunensis Pope and Hairston 138

Plethodon jordani teyahalee Hairston . .. 1 0

Plethodon jordani clemsonae Brimley . . ... 141

Plethodon glutinosus glutinosus (Green) . . 193

Plethodon glutinosus albagula Grobman . . . 196

SUKMRY .................. ....... .. 197

LITERATURE CITED ................ ..... 198






iii


LIST OF FIGURES

Figure Page

1. Lateral and dorsal views of the trunk vertebrae of
representatives of the three major groups of the
genus Plethodon. . . . . . . . . . 23

2. Suggested phylogeny of the major subdivisions of the
genus Plethodon. . . . . . . . . . 26

3. Suggested phylogeny of the Western Plethodons . . . 33

4. The distribution of the subspecies of Plethodon
vandykei in Washington, Oregon, and Idaho. . . 36

5. The distribution of Plethodon dunni in Oregon and
southwestern Washington, . .. ... .. . 0

6. The distribution of Plethodon vehiculum in Oregon,
Washington, and BritishColumbia . . . . . 42

7. The distribution of Plethodon products in California
and Oregon . . . . . . . . . . . 45

8. The distribution of Plethodon neomexicanus in New
Mexico . . . . . . . . . ... 45

9. Suggested phylogeny of the Eastern Small Plethodcns . 52

10. The distribution of Plethodon welleri in North
Carolina, Tennessee, and Virginia. . . . . .. 52

11. The distribution of the subspecies of Plethodon
richmondi. . . . . . . . . . . 63

12. The distribution of the subspecies of Plethodon
dorsalis . . . . . . . 70

13. The distribution of the subspecies of Plethodon
cinereus . . . . . . . ..... .. 77

14. Vomerine teeth of 269 peninsula Florida P. glutinosus
plotted against snout-vent length. .. . . . 83

15. Vomerine teeth of 45 P. glutinosus from the Coastal
Plain of Virginia and North Carolina plotted
against snout-vent length. ... . ........ 83

16. Vomerine teeth of 115 P. j. jordani plotted against
snout-vent length .. . . . . . .. 8










Figure Page

17. Vomerine teeth of 60 P. w. wehrlei plotted against
snout-vent length. .. .. . .......... 84

18. Vomerine teeth of 39 P. caddoensis plotted against
snout-vent length. . . . . . . . 8

19. Suggested phylogeny of the Eastern Large Plethodans . 8

20. The distribution of the subspecies of Plethodon wehrlei 95

21. The distribution of the Plethodon yonahlossee Group . 102

22. The distribution of the subspecies of Plethodon ordani 112

23. The distribution of the dark-chinned (glutinosus) and
light-chinned (albagula) populations of P. glutinosus
in central Texas . -. . . . . . . 189

2h. The distribution of Plethodon glutinosus in eastern
United States . . . . . . . . . 195









INTRODUCTION


The North American genus Plethodon presently has more recog-

nized forms than any other genus of salamanders. It is the type genus

of the lungless family Plethodontidae, reviewed so ably by Dunn in 1926.

At present, this is the most successful salamander family; over half of

the living species of the Order Caudata are plethodontids. North Amer-

ica is the center of the distribution of the family, but one genus,

Hydromantes, also occurs in Europe, and members of several genera enter

the Neotropical region. Salamanders of this family occupy habitats,

ranging from strictly aquatic cavernicoles (Typhlomolge and Haideotriton)

and mountain stream dwellers (Leurognathus) to others like Plethodon,

which are completely terrestrial, even to the extent of laying their eggs

on land. Dunn believed that Plethodon is the most primitive genus in the

attached-tongue branch of the family, and that Hemidactylium, Ensatina,

Batrachoseps, and Aneides are more specialized derivatives of a Plethodon-

like ancestor.


In 1926, only eleven forms of Plethodon were known to Dunn.

In 1943, Bishop listed 17 species (one has since been removed from the

genus) and two subspecies (both are now considered different species).

In 1944, Grobrnan reviewed the distribution and relationships of the

eastern section of the genus, including some sixteen species and sub-

species. There are now twenty-five forms recognized in eastern North

America, with seven more in the western United States and Canada.


Grobman (1914: 266) divided the eastern forms into two groups,

the Large Plethodons and the Small Plethodons. He suggested that these






-2-


groups might actually represent distinct genera or subgenera, but he

reserved judgement in this matter until the relationship of the west-

ern species with the eastern forms could be determined. One of the

purposes of the present study is to determine these relationships by

a comparative study of the morphology of all the species of the genus

Plethodon.


Of the twenty-five genera in the family Plethodontidae, only

two others show as great or greater disjunctions in their distribu-

tions as that found in Plethodon. These are Hydromantes, with two

forms in Europe and three species in California, and Aneides, with

four species in western North America and one in the Appalachian Moun-

tains of the eastern United States. In the past two decades, several

new plethodons have been discovered in both eastern and western Iorth

America. A review of the relationships of these forms offers a valu-

able opportunity to study the evolution of this important group of

North American salamanders.


The importance of examining plethodons in life has been em-

phasized by most recent workers. Many species, particularly the Large

Eastern forms, are extremely difficult to identify after years of pres-

ervation. In few other vertebrates are differential characters between

species so rare. For this reason, a special attempt was made to obtain

living specimens of each form. Twenty-five of the thirty-two forms

recognized herein have been studied alive.


The list of persons who have contributed specimens to this

project is long and I wish to express to each of them my sincerest

thanks and appreciation for their valuable aid: Charles G. Adams,






-3-


Walter Auffenberg, Herbert Barden, Albert P. Blair, E. E. Brown,

Jerry and Esther Brown, Douglas M. Burns, Archie Carr, A. H. Chaney,

Roger Conant, John W. Crenshaw, J. C. Dickinson, John Dolan, Herndon

Dowling, Philip C. Dumas, Helen T. Gaige, M. Ruth Gilreath, Arnold B.

Grobman, T. P. Haines, Keith L. Hansen, Robert Hellman, Albert H.

highton, Thelma Howell, Leslie Hubricht, Robert Humphries, Richard M.

Johnson, James Kezer, J. D. Kilby, James Knepton, H. D. Leake, Edwin

H. McConkey, John S. Mecham, Sherman A. Minton, Wilfred T. Neill,

Howard T. Odum, Larry H. Ogren, David Pettus, John Quinby, George

Rabb, Neil D. Richmond, William Riemer, Bernard Roseman, Doug Rossman,

Albert Schwastz, Robert S. Simmons, Ralph Sinclair, William Sloan,

Peter Smith, Bette Starner, Charles J. Stine, Walter Stone, Virginia

Switzer, Sam R. Telford, G. M. Thorp, Gordon Thurow, Don Tinkle,

Arnold and Rusty Van Pelt, Charles F. Walker, Tilliam Witt, and Harry

Yeatman.


Most of the material given me by these persons has been

deposited in the University of Florida collection. This collection

has formed the nucleus of the material on which this study is based.

Some additional specimens have been borrowed from other collections,

but I did not attempt to follow the course of the conventional monog-

rapher and examine every specimen available in museums, simply for the

sake of completeness. The material borrowed from other museums in-

cludes the following: Western Plethodons from the University of

California; Texas P. glutinosus from Bryce C. Brown, Ottys Sanders,

John S. Mecham, and the Strecker LAseurm; P. d. angusticlavius, P.

glutinosus, P. ouachitae, and P. caddoensis from the University of

Arkansas; P. c. serratus, P. w. wehrlei, and P. w. dixi from the









Chicago Natural History Museum; P. glutinosus, P. w. wehrlei, and P.

richmondi from the Carnegie useum; P. cinereus from the Museum of

Comparative Zoology; P. richmcndi from the United States national

Museum; P. glutinosus and P. 1. rabunensis from the Charleston Euseum;

P. dorsalis from the University of Georgia; P. richmondi and P. glutin-

osus from the Cincinnati Society of Natural History; P. dorsalis from

the Ross Allen-'ilfred T. Neill collection; and the entire Flethodon

collection of the Great Smoky Mountains National Park.


For the loan of material in their care, I wish to thank the

following museum officials: Neil D. Richmond, Carnegie museum (CM);

Albert Schwartz, Charleston Museum (ChM); Robert Inger, Chicago Natural

History Vhseum (CNHM); Ralph Dury, Cincinnati Society of Natural History

(CSNH); Arthur Stupka, Great Smoky Mountains National Park (GSUNP);

Arthur Loveridge, Museum of Comparative Zoology (MCZ); woilfred T. Heill,

Ross Allen Reptile Institute (ERA-TTN); Bryce C. Brown, Strecker Museum

(SM); Ierndon Dowling, University of Arkansas (UA); Bernard Martof,

University of Georgia (UG); William Riemer, University of Florida (UF);

Charles F. Walker, University of Michigan, Museun of Zoology (U1:Z);

and Doris 1. Cochran, United States National Museum (USNM). The fol-

lowing individuals have generously let me borrow material in their

private collections: Bryce C. Brown (BCB); John S. Mecham (JSM); and

Ottys Sanders (OS).


In addition I have greatly benefitted from stimulating dis-

cussion of some of the problems which have arisen during the course of

this study with the following persons: Drs. Robert Bader, Pierce

Brodkorb, Archie Carr, John W. Crenshaw, J. C. Dickinson, Richard A.


- 4-










Edwards, Coleman J. Goin, howard T. Odum, UVilliam RLeraer, H. K.

Wallace, and Messrs. Walter Auffenberg, Robert Hellman, Richard M.

Johnson, and Tilfred T. Neill. 1y wife, Anne, besides being patient

and sympathetic while undergoing considerable personal inconvenience

during many long hours of field work in the various hot, wet, cold,

and mosquito-infested places where these animals live, has also mate-

rially contributed to the project by typing, filing, proofreading, and

especially by taking practically all the color notes on geographic

variation of the P. glutinosus group. The Chairman of nm Graduate

Supervisory Conmittee, Dr. Arnold B. Grobmrn, has been a constant

source of intellectual stimulation, encouragement and helpful advice

and criticism.



METHODS


The importance of studying living plethodons, because of the

usual loss and alteration of their pigments in preservatives, has al-

ready been mentioned. It is almost impossible to study geographic var-

iation in pigmentation without considerable field work, and it was ini-

tially hoped that this could be done with all the forms in the genus.

Unfortunately, several of the forms have not been seen alive and so

our knowledge of their geographic variation has not been augmented.

However, I have been able to do a considerable amount of field work

with some of the Eastern Large Plethodons, and the result has been a

considerable amount of new information concerning them. I believe

that when similar studies of other species are made, they will be

found to vary as much as glutinosus and jordani in pigmentation char-

acters.






-6-


A perusal of the literature on this genus will disclose

that most workers have given considerable weight to variation in the

number of costal grooves., A careful study of the literature indi-

cates, however, that there is not agreement in the reports of number

of costal grooves in many species. The reason for this was apparent

to the writer when I failed to obtain consistent counts on the same

specimens counted at different times. A method for accurately deter-

mining the true variation in body segmentation would be a necessary

preliminary to the use of this character in studying relationships.

Since the costal grooves show a direct correlation with the number of

vertebrae, a method of counting the number of trunk vertebrae by the

use of X-ray photographs was devised. As an outgrowth of this study,

a method for counting costal grooves which will accurately reflect

the body segmentation of salamanders of this genus will be reported

below.


'any other characters have been used in the study of the

systematics of this genus. As far as possible, these have been re-

studied using much new material that has recently become available.

Several nomenclatorial changes will be suggested based on an attempt

to best indicate the biological relationships of these organisms.


The results of this study have clearly indicated that there

are three major natural subdivisions of the genus Plethodon. These

would probably be considered subgenera in most animal groups, but

herpetologists have rarely used subgenera in their classification.

Although the use of subgenera would be helpful in this case, conmon

names will be used for these groups in conformity with current herpe-

tological practices. They will be referred to as the eastern n Pleth-






-7-


odons," "Eastern Small Plethodons," and "Eastern Large Plethodons."

Each of these subdivisions of the genus is further divided into

species groups consisting of species which are more closely related to

each other than they are to any other similar group. In a few cases,

species which are morphologically quite distinct from any other species

in their section of the genus have been segregated into a species

group consisting of a single species.


For each taxon, information on the morphology, variation,

and distribution is given, followed by a synonomy, data on the type

specimen, diagnosis of the form, and a description of the pigmentation,

segmentation, number of vomerine teeth, and size. Detailed descrip-

tions of several hundred specimens were made during the course of this

study. For most forms, similar data are available in Bishop (1943) or

Stebbins (1951) or in the original description. It is unnessary to

repeat these here, since the concern is variation of populations, not

detailed descriptions of individual specimens.

Dunn (1926) presents fairly complete synonomies for each of

the forms known at that time. Therefore the large number of refer-

ences on the distribution and habits of the more common forms are not

included here. An attempt has been made to include the first refer-

once to each combination of names, as well as most of the papers deal-

ing'.with the systematics of each form. Check lists have usually been

omitted, except when now combinations of names or other new information

is presented. Consistancy has not been a goal, and some papers deal-

ing with habits or distribution have been included in the synonomies

of little known species, while similar papers on well known forms






- 8 -


that do not contribute new information have been omitted.


The locality maps have been prepared mainly as an aid to

the discussion of the distribution of the various species groups.

They are based on literature records as well as specimens examined

by the writer. Maps showing the distribution of many of these forms

are available elsewhere, but there have been many changes in the

taxonomy since the publication of some of these, and it seems desir-

able to include them here in spite of the fact that there is some

repetition. New information on the geographic distribution of sever-

al of the forms is included on some of the maps.


Seventeen subspecies are recognized in this paper. An

examination of the distribution maps indicates that several of the

polytypic species exhibit terminal raciation and most of these

races are isolated from their nearest relatives by areas of unin-

habited country. This is true of the races of P. vandykei, P.

dorsalis, P. cinereus, and to some extent, P. glutinosus. The sub-

species of P. wehrlei are poorly defined, and need more study. There

do not appear to be natural barriers between some of the subspecies of

P. richmondi and P. jordani, and there is evidence that intermediate

populations are present between some of the races. A more detailed

consideration of raciation in both of these species is given below.


THE RELATION BETWEEN NUMBER OF COSTAL GROOVES AND

TRUNK VERTEBRAE IN PLETHODON


Radiographs of series of specimens of all the species in

this genus have indicated that the number of trunk vertebrae in a






-9-


single population is remarkably constant. (Since there is little

differentiation of the salamander body vertebrae into regions, Francis

(1934) suggests that all precaudal vertebrae, except the atlas and the

sacrum, be called trunk vertebrae.) There is never a variation of

more than three trunk vertebrae in a single population and with few

exceptions, the intermediate figure has a very high frequency of

occurrence. The value of this character in studying variation becomes

apparent when it is found that a difference of a single vertebra be-

tween two populations is easily detectable and has been used success-

fully as a key character to separate a high proportion of specimens of

two contrasted forms.


A method of counting costal grooves that would accurately

reflect the number of trunk vertebrae would be much more effective in

the taxonoTic study of this genus. At present, their use is rather

limited, since they are rarely counted consistently by different

workers. Pope (1950: 102) correctly summarizes the existing situa-

tion by stating that "variation of a magnitude of one or two grooves

will be meaningless unless the same worker has made all the counts

and done so .ith great care." The method described here has been

found to correctly correspond with the number of trunk vertebrae with

over 90% accuracy.

The atlas is not related to any costal grooves. The first

trunk vertebra is located just anterior to the gular fold and its rib

does not appear to be associated with the gular fold or with any of

the costal grooves. The rib of the second trunk vertebra is located

in the ryoseptum of the first costal groove. The external position

of this groove varies somewhat, but is usually close to the front






- 10 -


limb insertion. If the first costal groove is poorly defined or absent,

as often occurs when it is located directly over the front limb inser-

tion, it should be counted, as the space obviously corresponds to a ver-

tebra whether the groove is visible or not. The individual variation in

the position of the first costal groove is probably due to the variation

in the position of the pectoral girdle relative to the vertebrae. The

girdle may be located opposite the second trunk vertebra, between the

second and third trunk vertebrae, or opposite the third trunk vertebra.

The ribs of the third trunk vertebra extend posteriorly so that the

second coastal groove is always posterior to the front limbs.


There is a one-to-one relation between the remaining body ver-

tebrae and the costal grooves, except in the case of rare aberrations

(one vertebra possessing two or more pairs of ribs, or one vertebra

possessing a rib on only one side, in which case a corresponding costal

groove is present only on that side). The last pre-sacral vertebra

(usually the only trunk vertebra which does not possess ribs) is repre-

sented by the groove just anterior to the insertion of the hind limbs.

Often this groove joins ventrally the one just preceding it so that on

the lower sides there is only onegroove which is forked dorsally. Both

grooves should be counted, since they correspond to two separate verte-

brae. The groove present over the hind limb insertion (sometimes weakly

developed or absent) corresponds to the sacral vertebra, and each groove

on the tail corresponds to a caudal vertebra.


There is much more individual variation in the position of the

sacral vertebra in relation to the pelvic girdle than there is in the

relation of the shoulder girdle to the second and third trunk vertebrae.






- 11 -


The sacral vertebra may be located so far anterior to the pelvic girdle

that the first caudal vertebra is opposite the hind limbs. It may also

be slightly anterior, opposite, or slightly posterior to the pelvic

girdle. Occasionally when it is posterior to the girdle, the costal

groove corresponding to the last trunk vertebra is located over the

hind limb. This is the major source of error in attempting to accurately

correlate the number of costal grooves with the number of trunk verte-

brae. Fortunately, however, fewer than 10% of the specimens examined

were in this category. Using this method, costal groove counts were

made on 85 specimens of several species of the genus Plethodon (includ-

ing specimens possessing 15 to 22 trunk vertebrae), and 93% of the

counts accurately represented the number of trunk vertebrae obtained

from X-ray photographs. Since the first trunk vertebra is not asso-

ciated with a costal groove, the number of costal grooves is always one

less than the number of trunk vertebrae. It would therefore appear

that this method can be used advantageously to obtain an accurate es-

timate of the number of trunk vertebrae of all the species of the genus

Plethodon.


Occasionally the sacral rib may attach to one vertebra on one

side of the animal and to the following vertebra on the other side.

Rarely, there are two sacral ribs issuing from two successive vertebrae

on the same side of the animal. The suggested method of counting costal

grooves is of no value in detecting such abnormalities.





- 12 -


PIGMENTATION IN THE GENUS PLETHODON


Pigmentation in living specimens was studied with the aid of

a dissecting microscope. Although there is great variety in the color-

ation of the animals included in this genus, the actual different types

of pigments are few. No histological or biochemical studies of the

pigments have been made, thus similarity in the appearance of the pig-

mentation is the basis for the above statement. Three main types were

identified and are called melanophores, guanophores, and lipophores,

following Ctebbins (1951).


Melanophores are present in all the forms in the genus. They

are responsible for the dark ground color of these salamanders. The

other pigments generally occur in gaps in the melanophore ground color.


Guanophores are responsible for the white and brassy spots,

present on many of the species. There appears to be little difference

in the structure of the different colored guanophores, but mainly a

difference in the amount and color of light reflected from the spots.

The iridescence characteristic of animals with "brassy" "dorsal spots

appears to be centered in small round crystalline structures found at

intervals along the pseudopodia of the guanophores. The number of these

crystals seems to determine the amount of the iridescence that has been

variously described by different workers as "brassy flecking," metallic

golden spotting," "golden blotches," "bronzy mottling," and "frosting."

This type of guanophore pigmentation is present in the iris of most of

the Eastern Small Plethodons and the Western Plethodons, and is present

on the dorsum of many of the species. It is responsible for the brassy

dorsal flecks of glutinosus, ouachitae, dixi, clemsonae, popei, netting,







- 13 -


cinereus, polycentratus, dorsalis, welleri, and vehiculum. In welleri,

these guanophores are concentrated to form dense clusters. In Lluti-

nosus, they are usually associated with other white guancphores. In

the other forms they are scattered over the back and are not clumped

into spots. Brassy flecks are rarely found other than in the iris or

on the dorsum of salamanders of this genus.


Guanophores that lack the brassy iridescence are co-mon on

the belly and sides of many spocics, and are also present on the dorsum,

occasionally occurring there with the brassy type. They have a much

greater tendency to be clumped together to form larger spots than do the

brassy flecks, but are occasionally found singly. In glutinosus, for

example, it is often possible to see, on the same animal, every type

of intermediate between the brassy type and those which lack the brassy

iridescence.


The white guanophores are characteristically found on the

dorsum of glutinosus, ouachitae, cinereus, polycentratus, popei,

dorsalis, and vehiculum. They are present on the sides of almost all

of the eastern species (except metcalfi and melaventris), and on the

bellies of all the Eastern Small Plethodons. Often these lateral and

ventral spots have a yellowish color, but this is not due to the presence

of brassy flecks.


Lipophores do not have the structure of guanophores in that

they lack the pseudopodia vhich can easily be observed in the guano-

phores. The red color of jordani, shermani, wehrlei, yonahlossee,

ouachitae, cinereus, polycentratus, serratus, dorsalis, and vehiculum





- 14 -


appears to be due to the same type of lipophore pigment. The dorsal

band of yonahlossee is a darker color because of the additional pres-

ence of melanophore pigment. Lipophores may also be yellow in color,

as in some cinereus, vehiculum, and dunni.


The variety of colors present in the genus seems to be due

entirely to variation in the abundance of these pigments or various

combinations of the three. In some forms, the lipophores or guanophores

or both are lacking. There is also variation in the concentration of

melanophores. These pigmentation characters may vary somewhat withinn a

species, both individually and geographically, but are fairly uniform in

most forms, enabling a person familiar with living specimens to easily

identify most salamanders by the color pattern alone. The phylogenetic

significance of the distribution of these pigments in the various pleth-

odons is discussed below in the accounts of the various forms.



KEY TO THE SALAMANDERS OF THE GENUS PLETHODON


The key is based mainly on the average number of trunk verte-

brae occurring in each of the forms. Before using this key, it is sug-

gested that the section on the method of counting costal grooves that

accurately reflects the number of trunk vertebrae be read. A small per-

centage of specimens of each form may not be correctly identified on

this basis, but a small series will usually key out correctly. Ranges

are included and locality data may proove more helpful in identifying

preserved specimens than pigmentation characters.


1 a Costal grooves usually 14 ................. 2

b Costal grooves 15 or more . . . . . . .... 4








2 a Ventral color reddish (Multnomah County, Oregon, and Ska-

mania County, Washington) . . ..... P. v. larselli

b Ventral color not reddish ... ... ... ..... 3

3 a Yellow or orange dorsal stripe contrasts sharply with the
lateral black ground color; the proximal segments of the

limbs dark in color (Kootenai County, Idaho) P. v. idahoenois

b Ground color light, not contrasting sharply with the dor-

sal stripe; yellow lipophore pigment similar to that found

on the dorsum present on the proximal segment of the

limbs (western Jashington) . .... P. v. vanykei

4 a Costal grooves usually 15 (western Oregon and southwestern
Washington) . . . . . . . . P. dunni

b Costal grooves 16 or more .... ... . . . 5

5 a Costal grooves usually 16 .. .... .. ... 6

b Costal grooves 17 or more . . . ........ 20

6 a Belly mottled with yellow or red, white and black; size small,

usually under 50 mm. snout-vent length; often a red, tan,

or yellow dorsal stripe (southwestern British Columbia, in-

cluding Vancouver Island, western '",ahirnton and western

Oregon) ................... P. vehiculum

b Belly usually dark, at least posteriorly, or with scattered

small white ventral spots; size usually larger (except

welleri and caddoensis); dorsal stripe usually absent

(except yonahlossee and ouachitae) (eastern United States) 7

7 a Red pigment present on back, legs, or cheeks . . ... 8

b No red pigment present on animal . .... ...... 11


- 15 -





- 16 -


8 a Red pigment confined to sides of head or legs in adults 9

b Red pigment largely restricted to dorsum . . .. 10

9 a Red pigment most abundant on sides of head (Great Smo1ky

Fountains of Tennessee and North Carolina) . jordani

b Red pigment most abundant on legs (Mantahala Mountains,

North Carolina) . . . . ..... P. sherani

10 a White pigment lacking in dorsal stripe (Blue Ridge Aoun-

tains of southwestern Virginia, northeastern Tennessee,

and northwestern North Carolina) . . . P. yonahlossee

b Abundant white pigment occurring within the dorsal stripe

(Ouachita mountains of Arkansas and Oklahoma) P. ouachitae

11 a Size small, adults not over 50 Im. snout-vent length;

back with large coalescing iridescent brassy spots,

usually covering about half the area of the dorsum

(Blue Ridge Province of southwestern Virginia, north-

eastern Tennessee and northwestern Ntorth Carolina) P. wolleri

b Back without dorsal brassy spots, or if present, they

are small in size and cover less than one quarter of

the area of the dorsur . .. ....... ... 12

12 a Body entirely black, guanophores and lipophores absent . 13

b Dorsum and/or sides with guanophore spotting . . .. 1

13 a Belly much lighter than dorsum (mountains of western North

Carolina and adjacent Tennesece and Virginia) P. j. metcalfi

b Belly almost as dark as dorsum (southwestern North

Carolina) . . . . . . .. .. P. j. melaventric





- 17 -


14 a Back with large conspicuous white or brassy dorsal spots 15

b Back without large conspicuous guanophore spotting, or if

present, the spots are of very small size . . . 17

15 a Melanophore pigmentation on chin greatly reduced, compared

to belly ....................... 16

b Melanophore pigmentation on chin similar to that on belly

(eastern United States from southern New York to northern

Florida, west to eastern Louisiana, Illinois, Lissouri,

eastern Oklahoma, and the Balcones Escarpment in Texas)

. . . . . . . . . . . lutincsus

16 a Dorsum with white spots only (Balcones Escarpment in

east central Texas) . . . . ... . P. albagula

b Dorsum with large white spots and smaller brassy flecks

(Caddo Mountains of Arkansas) .. . . . P. caddoensis

17 a Dorsum with very small white or brassy spots . . . 18

b Dorsum black, without any guanophore spotting . . . 19

18 a Dorsum covered with tiny brassy flecks (vicinity of

Jocassee, South Carolina) . . . . P. J. clemsonae

b Dorsum with very tiny scattered white spots (Tusquitee

and Snowbird Mountains of western North Carolina)

. . . . . . . . . . P. P. teyahalee

19 a Belly much lighter than ground color of back (Unicoi

Mountains of western North Carolina and eastern

Tennessee) . . . . . . . . P. j. unicoi

b Belly nearly as dark as dorsal ground color (mountains

of northeastern Georgia . . .... . P. rabunensis






- 18 -


20 a Costal grooves usually 17 . . .. .. . ... . 21

b Costal grooves 18 or more . . . . . . . .. 23

21 a Large red spots on dorsum of adult (southwestern Virginia)

* * *. * . . . . . . . P. w. jacksoni

b Red spots absent from dorsum of adult . . . . . 22

22 a Dorsum with numerous white and brassy spots (Roanoke

County, Virginia) . . . . . .... P. w. dixi

b Dorsum with very small white or brassy spots (Cattaraugus

County, New York, south through western Pennsylvania,

adjacent Ohio, and West Virginia) . . . P. w. wehrlei

23 a Costal grooves usually 18 . . . ....... .. 2L

b Costal grooves 19 or more . . . . . . . . 27

24 a Size large, up to 66 mm. snout-vent length (northwestern

California and southwestern Oregon) . . . P. products

b Size small, up to 45 mm. in snout-vent length (eastern

United States) . . . . . . . . . 2

25 a Belly mottled with red, yellow, white, and black pigment 26

b Belly black, with small white spots (Cheat Mountains of

West Virginia) . . . . . . . . P. r. nettingi

26 a Dorsal stripe very narrow, less than 1/3 the width of the

body (southwestern Missouri, northwestern Arkansas, and

adjacent Oklahoma) . . . . . d. angusticlavius

b Dorsal stripe much wider than 1/2 the width of the body,

edges of stripe very irregular (southern Illinois, Indiana,

and southern Ohio, south through Kentucky and Tennessee to

northern Alabama and northwestern Georgia) P. d. dorsalis






- 19 -


27 a Costal frooves usually 19 .............. . 28

b Costal grooves 20 or more . . . . . ..... 30

28 a Fifth too on hind foot usually with one phalanx (Jemez

fountains Now 'oxico) . . . . P. neomexicanus

b Fifth too on hind foot with two phalanges (eastern North

Amorica) . . . . . . . . . 29

29 a Dorsal red stripe with straight edges (southern Canada,

south to torth Carolina, eastern Kentucky, southern

Illinois, and eastern Missouri) . . . P. c. cinereus

b Dorsal red stripe with serrations corresponding to each

costal re (western Arkansas and eastern Okla-

homa) . . . .... . ... .. P. c. serratus

30 a 7;: pi rent present on sides and dorsum (northwestern

-r: ia) .............. P. c. polycentratus

b No red :i -cnt on animal ........... .. . 31

31 a Costal grooves usually 21 or more (western Pennsylvania,

south ni Ohio, eastern Kentucky, south to northwestern

Vir,i .) . . . . . . . . P. r. richmondi

b Costal r .ves usually 20 (southwestern Virginia, north-

western north Carolina, and adjacent Kentucky) P. r. popei





- 20 -


SYSTEMATICS


Plethodon Tschudi

Plethodon Tschudi (1838: 58). Genotype (by original designation):

Salamandra glutinosa Green.

Phatnomatorhina Bibron in Bonaparte (1839). (Substitute name)

Sauropsis Fitzinger (18h3: 33). (non Sauropsis Agassiz, 1832, Jahrb.

Min., 3: 1l2). Genotype (by original designation):

Salamandra erythronota Green.


Diagnosis;- Plethodontidae with tongue attached in front; premaxillae

separate; teeth on posterior portion of maxillae; tail not constricted

at base; five toes on the hind feet; no palmar tubercles; terminal

phalanges normal; and no aquatic larval stage.


According to Dunn (1926), the closest relatives of Plethodon

are Batrachoseps, Ensatina, Aneides, and Hemidactylium. All four of

these genera differ from Plethodon in several fundamental characteristics.

Batrachoseps and Hiemidactylium possess only four toes on the hind feet.

Ensatina and Ilemidactylium possess a basal constriction of the tail.

Ensatina has palmar tubercles. The premaxillae are fused in Aneides and

Batrachoseps (except B. wrighti. Hemidactylium has an aquatic larval

stage. Aneides lacks teeth on the posterior portion of the maxilla and

has expanded terminal phalanges. Dunn (1926: 22) believed that Plethodon

is the most primitive genus in this group of genera and that the others,

with the possible exception of Ensatina, are more specialized than

Plethodon. The genus Plethodon is the largest in number of species, and

there is more divergence within the genus than in the other related

genera. This might be considered evidence for, but not necessarily

proof of, a greater age for this genus.






- 21 -


Grobnn (IPo9: 266) suggests that the relationship between

the Eastern : -r Small Plethodons is not close and lists size

and costal groove c forenccs which distinguish them. Actually there

is some c.r-r. bet cen the Eastern Large and Small Plethodons in

these characters, -ut there are other important differences between the

two groups. nectal gland is much better developed in male Eastern

Large Plethodcn~ th n in the nastern Small Plethodons. The worm-like

body and shooter 13 of the sternn Small Plethodons is characteristic.

The Eastern -. lthodons have fewer teeth and there is a great deal

of variation in te number of trunk vertebrae within the group (range

16-2h), heres the ;astern Large Plethodons show very little variation

(range 16-19). Tiere is more webbing on the toes of the small forns

than in the 1- 7 cies. The Eastern Large Flethodons have an un-

pigmented --rietal eritoneun, while in the srall species the peri-

tonoum is :1 '"- rith melanophores. The differences in the struc-

ture of the ver ebrae are discussed below.


One .iore, P. wehrlei, is usually included with the Eastern

Large 'lethodonr on the basis of size, but in several ways it is inter-

mediate between the two groups. It has more costal grooves and fewer

teeth than other Saster Large Plethodons. Its toes are webbed as in

the -astern :.ll lethodons and the peritoneum has a few melanophores.

Kere it not for the intermediate character of this species, the two

groups should probably be recognized as distinct genera, but the some-

what inter. ei te nature of wehrlei would seem to indicate that they

have not "cc ne sufficiently distinct to justify such an action. The

two -rc. could best be regarded as subgenera, but to conform with

current prtise, the common names, Eastern Large Plethodons and Eastern






- 22 -


Small Plethodons, will be used in this paper. Although P. wehrlei

possesses more characters that would link it with the Eastern Small

Plethodons than do any of the other Eastern Large Plethodons, it is

probably more closely related to members of the latter group. There-

fore, it is included as a separate species group under the Eastern

Large Plethodons. Its intermediate position is important, however, in

linking the two groups.


During studies on the osteology of this genus, certain dif-

ferences in the vertebrae of the two eastern sections of the genus

have been noted. The height of the vertebrae of the Eastern Small

Plethodons is proportionately less and the vertebrae usually lack the

neural spines that are present on those of the large eastern species

(see figure 1). P. wehrlei is not intermediate in this regard, but

closely resembles the other Eastern Large Plethodons. The vertebrae

of all the eastern species have been examined except for caddoensis

and richmondi.


To investigate the relationship of the western forms with

those in eastern North America, each of the above differential charac-

ters was studied in all five of the western species. As with the east-

ern forms, the size varies within the group, but four of the five west-

ern species are as large as most of the Eastern Large Plethodons. The

number of trunk vertebrae varies considerably in the western forms

(range 15-20). The mental gland is poorly developed in all the Western

Plethodons. The body form is variable, ranging from short and stout in

vandykei to very elongate in neomexicanus. The number of vomerine teeth

is low in the western forms. The toes of two species (dunni and vehi-






- 23 -


B
I mm


c


Figure 1. Lateral and dorsal views of the trunk vertebrae of rep-
resentatives of the three major groups of the genus

Plethodon. A. P. glutinosus. L. P. welleri

C. P. dunni


1!


1-m






- 2h -


culum) are ver; slightly webbed, while the other chree species have

webbed toes. .' 2ritoneum of all of the westernr n Plethodons is

pigmented vith nel nophores. The vertebrae of the western forms are

quite different from both eastern types (P. neomexicanus has not been

examined). h- are proportionately longer and have longer transverse

processes than of the eastern species. As a group, the western

Plethodons are more variable, and in at least one character, the

structure of the vertebrae, they are very distinct from both eastern

sections of the gerus. It would appear that the v:estern and Eastern

Plethodons have been separated for a long time, and that both have

undergone considerable speciation during this period.


In several ways, the Eastern Small Plethodons resemble the

Western Flethodons more closely than do the Eastern Large Plethodons.

The red or yellow dorsal stripe is more common in both groups than it

is in the Eastern Large Plethodons. Both have a great amount of

vari;.tion in the number of trunk vertebrae and degree of elongation of

the body. Loth h've low vo-lerine teeth counts and a pigmented peri-

toneui. Both h-ve a less well developed mental gland than the Eastern

Large "lethodons (except for dorsalis). It would appear that the

Eastern tarre ilethodons are the more specialized fonas, with a larger

number of vonerine teeth, loss of pigmentation in the peritoneum, and

increase in the development of the mental gland. The fact that P.

wehrlei possesses characteristics of both groups would indicate that

both v.ere derived frovi a common ancestor. This conron ancestor was

probably nore like the Eastern Small Plethodons and the Western Pleth-

odons in ost of its characteristics, since it would be unlikely that

these two groups would have independently converged toward each other






- 25 -


in so many ways from an ancestor that was similar to the Eastern Large

Plethodons as suggested by Dunn. The relationships of the three groups

would appear to be best indicated by a phylogeny similar to that shown

in figure 2.


The relationship of the Western Plethodons with the other

plethodontid genera in western North America needs further study. It

may be that the Western Plethodons are more closely related to Batra-

choseps, Ensatina, or western Aneides than they are to any of the

Eastern Plethodons. The western plethodontid salamanders may have been

isolated from their eastern relatives for a long period of time. The

fact that two groups now included in the genus Plethodon, one in east-

ern North America and the other in the western part of the continent,

have both retained many primitive characteristics, does net necessarily

mean that they are still generically related to one another. The fact

that each of these groups (the Western and Eastern Plethodons) has more

species than any other plethodontid genus in its region, as well as the

the fact that these species are so diverse, would support the view that

they have been separated for a long period of time. A review of this

entire problem is needed, but it would involve an investigation of the

characteristics of the genera Aneides, Batrachoseps, Ensatina, and

Hlemidactylium, and is beyond the scope of this study. Such an inquiry

should be completed before erecting a new genus for the Western Pletho-

dons, but this arrangement seems to be indicated by the present incom-

plete information.


The systematic arrangement of the genus Plethodon suggested

in this paper is as follows:







- 26 -


Eastern Large
Plethodons


Figure 2.


Eastern Small
Plethodons


Suggested phylogeny of the major subdivisions of the


genus Plethodon.


Western
Plethodons





- 27 -


Western Plethodons

Plethodon vandykei Group

Plethodon vandykei vandykei Van Denburgh

Plethodon vandykei idahoensis Slater and Slipp

Plethodon vandykei larselli Burns

Plethodon vehiculum Group

Plethodon dunni Bishop

Plethodon vehiculum (Cooper)

Plethodon products Group

Plethodon products new name

Plethodon neomexicanus Group

Plethodon neomexicanus Stebbins and Riemer

Eastern Small Pletho'ons

Plethodon welleri Group

Plethodon welleri alker

Plethodon richmondi richmondi Netting and Miittle:nan

Plethodon richmondi popei llighton and Grobman

Plethodon richmondi nettingi Green

Plethodon cinereus Group

Plethodon dorsalis dorsalis Cope

Plethodon dorsalis angusticlavius Grobman

Plethodon cinereus cinereus (Green)

Plethodon cinereus serratus Grobman

Plethodon cinereus polycentratus Ilighton and Grobman






- 28 -


Eastern Large Plethodons

Plethodon wehrlei Group

Plethodon wehrlei wehrlei Fowler and Dunn

Plethodon wehrlei dixi Pope and Fowler

Plethodon wehrlei jacksoni Newman

Plethodon yonahlossee Group

Plethodon yonahlossee Dunn

Plethodon ouachitae Dunn and IIeinze

Plethodon caddoensis Pope and Pope

Plethodon glutinosus Group

Plethodon jordani jordani Blatchley

Plethodon jordani metcalfi Brimley

Plethodon jordani shermani Stejneger

Plethodon jordani unicoi new subspecies

Plethodon jordani nelaventris Pope and Hairston

Plethodon jordani rabunensis Pope and llariston

Flethodon jordani teyahalee Hairston

Plethodon jordani clensonae Brimley

Plethodon glutinosus glutinosus (Green)

Plethodon p:lutinosus albagula Grobnan




- 29 -


The Western Plethodons


The Western Plethodons include five species, none of which,

except for dunni and vehiculum, appear to have close affinities. P.

vandykei, with three presently recognized subspecies, vandykei, larselli,

and idahoensis, occurs in coastal Washington, northwestern Oregon, and

northern Idaho. P. dunni is known from southwestern Washington and

coastal Oregon. P. vehiculum ranges on the coast from central Oregon to

southern British Columbia, including Vancouver Island. P. products

(formerly P. elongatus) occurs in a small area in northwestern Cali-

fornia and southwestern Oregon. P. neonexicanus is known only from the

Jemez Mountains of New Mexico.


Stebbins (1951) has recently summarized the knowledge of the

amphibians of western North America, and has given detailed descriptions

of all five species in life. Little new information on individual or

geographic variation can bo offered here since I have had no field ex-

perience with these animals and only four forms (idahoensis, dunni,

vehiculum, and products) have been examined in life. Reference should

be made to Stebbins' book for further information on these forms.


Radiographs of a series of each of the forms exceptt the re-

cently described P. v. larselli) were taken and the number of trunk

vertebrae in each form is shomn in table I. The usual number of trunk

vertebrae in each species of I.estern Plethodon is different, and none

of the known forms possess 18 trunk vertebrae as the modal number.


Except for vehiculum, all of the stern Flethodons are fairly

large in size. All but neomexicanus possess a stripe phase in the adult,

and all but dunni and vehiculum have webLed toes. The vomerine tooth






- 30 -


TABLE I


THE NUMBER OF TRUNK VERTEBRAE IlN -ST''I"J FORMS OF THE GFIIUS PLETHODON


Number of trunk vertebrae


Form


15 16 17 18 19 20


v. vandykei

v. idahoensis

dunni

vehiculum

Droductus

neomexicanus


10 32


1 15






- 31 -


counts of all of the western forms are low compared to Eastern Large

Plethodons of similar size; vehiculum and products have especially

low vomerine counts.


P. vandykei is unusual in possessing a parotid gland and in

having the lowest number of vertebrae in the genus. P. neomexicanus

is unusual in being the only species in the genus that has a reduced

fifth toe on the hind limbs.


Plethodon dunni and Plethodon vehiculum appear to be rather

closely related. P. dunni attains a larger size than P. vehiculum and

has more vomerine teeth. P. vehiculum usually has one more trunk ver-

tebra than dunni. P. dunni has more aquatic habits than vehiculum. The

color of the dorsal lipophores in the striped phase of the two forms is

different. The stripe of dunni is usually greenish yellow, while that

of vehiculum varies from reddish tan to yellow. The toes are very

slightly webbed in both and most other structural features are similar.


The other western Plethodons possess a considerable amount of

webbing on their toes. The amount of webbing on the toes does not ap-

pear to be correlated with aquatic tendencies, since the two most aqua-

tic forms, dunni and vandykei, represent extremes in the absence and

presence of webbing in the western forms. The forms vehiculum and ro-

ductus, both with more terrestrial tendencies, also differ greatly in

amount of webbing between the toes. Moreover, in the eastern United

States, some of the forms have webbed toes, while others do not, yet all

are terrestrial.


There is no doubt that dunni and vehiculum should be regarded





- 32 -


as distinct species, since the two occur sympatrically through most of

the range of dunni without any evidence of interbreeding. A study of

this relationship and the possible differences in the habitat niches of

the two forms, suggested by Stebbins (1951: 65), is much to be desired.


The forms, vandykei, products, and neomexicanus all seem to

differ from each other as much or more than species groups in the Eastern

Flethodons. The fact that they are so distinct morphologically makes it

difficult to determine-their relationships. In all probability, these

forms have been differentiating for a long period of time. There has

probably been a considerable amount of extinction of humid forest dwell-

ing western N'orth American amphibians due to climatic changes which have

occurred during or since the Tertiary. The present discontinuous dis-

tribution of this genus in the area, with only two species recorded in

the Rocky fountains, separated by almost a thousand miles, supports

this view. Without doubt there are probably other undiscovered forms

of this genus in the western United States. Many salamanders of the

region are difficult to collect, except during extremely favorable con-

ditions, and some may have been overlooked in spite of intensive col-

lecting. There remain many areas in which there has been very little

collecting, and these nay be profitably searched for members of this

genus. Lowe (1955: ?50), for example, believes that plethodontid sal-

amanders will be found in the higher mountains of Arizona because con-

ditions there are similar to those where they have been taken in other

areas.


The relationships of these salamanders would seem to be best

indicated by the phylogeny shown in figure 3.







- 33 -


dunni vehiculum products neomexiconus


Sug -ested phylogerW of the Vestem plethodons.


Figure 3.






- 34 -


Plethodon vandykei Group

Plethodon vandykei

This species is koon from the Coast Range, Olympic Mountains,

and Cascade Mountains of western ;ashington; Coeur d'Alene Lake, in

northern Idaho; and from Larch Mountain, iultnomah County, Oregon. The

Idaho population was described as a distinct species (idahoensis) by

Slater and Slipp (19O0: 38), but has been considered a subspecies of

vandykei by Lowe (1950: 93)-and more recent workers. Although the Idaho

and I.ashington populations of this species are usually believed to be

isolated from one another, Savage (1952: 183) suggests that they may be

connected by a corridor of high humid country along the international

boundary between Y.ashington and British Columbia. The two forms, idaho-

ensis and vandykei, apparently differ mainly in color characters.


In 1954, Burns discovered Plethodon vandykei in Ifultnomah

County, Oregon. Two specimens from Larch Mountain were unusual in pos-

sessing red bellies. A series of eleven specimens collected on the north

side of the Columbia River, at Archer Falls, Skamania County, Washington,

also agreed in coloration with the Oregon specimens and this red-bellied

form was described as the third subspecies of vandykei, P. v. larselli.


Stebbins (1951: 80-1) states that there are two color phases

of P. v. vandykei. The light phase has the color of the belly and sides

very similar to that of the dorsal stripe, while the dark phase has a

darker lateral and ventral pigmentation.

This species is usually found in very damp situations and thus

replaces P. dunni ecologically, as well as geographically. It has re-






- 35 -


cently been shown that their ranges do overlap slightly in Multnomah

County, Oregon (Burns, 1954: 85) and Pacific County, Washington (Storm,

1955: 64-5).

Plethodon vandykei vandykei Van Denburgh

Plethodon vandykei Van Denburgh (1906: 61). Dunn (1926: 151-3). Slater

(1933: 44). Bishop (1943: 275-8). Storm (1955: 64-5).
Plethodon vandykei vandykei Van Denburgh. Lowe (1950: 93). Stebbins

(1951: 80-4). Stebbins (1954: 56-7). Slater (1955: 132-3).

Type:- CAS 6910 (now destroyed), collected at Paradise Valley, Mount

Ranier National Park, -ashington, by E. C. Van Dyke, in July, 1905.

Diagnosis:- A Western Plethodon with 15 trunk vertebrae. It differs from

idahoensis in having a vider dorsal stripe, lighter ground color, and by

presence of yellow pigment like that found on the dorsum on the proximal

segment of the limbs.

Range:- Known from western 'ashington, from Clallam County south to Pa-

cific County and east to Pierce County (see figure 4).

Description:- This subspecies has not been seen in life and only four

preserved specimens were examined. Stebbins (1951: 80-1) gives detailed

color notes on this form.

Costal grooves usually number 14 and the trunk vertebrae 15.
In the available specimens, vonerine teeth range from 7 to 10 in a series.


The largest individual is 56 rm. in snout-vent length.





-36-


Figure h. The distribution of the subspecies of Plethodon vandykei
in Washington, Oregon, and Idaho.






- 37 -


Plethodon vandykei idahoensis Slater and Slipp

Plethodon idahoensis Slater and Slipp (1940: 38). Slater (1941: 81, 85,

103). Bishop (1943: 259-61). Hilton (19h8: 120).
Plethodon vandykei idahoensis Slater and Slipp. Lowe (1950: 93).

Stebbins (1951: 80-4). Stebbins (195s: 56-7).

Type:- USNi 110o5o, an adult male, collected at the northeast corner of

Coeur d'Alene Lake, Kootenai County, Idaho, at an elevation of 2160 feet,

by James R. Slater, on September 13, 1939.

Diagnosis:- A race of Plethodon vandkei in which the yellow or orange

dorsal stripe is narrower than in P. v. vandykei and contrasts sharply

with the lateral black ground color, and the proximal segments of the

limbs are dark in color.

Range'- Known only from the type locality in northern Idaho (figure 4).

Description:- The back has a dorsal orange or yellow lipophore stripe.

The rest of the animal is pigmented with melanophores, except for nel-

anophore gaps on the chin where there are yellow lipophores. There are

also brassy guanophores in the iris, and a few scattered white guanophores

on the belly and sides.

The costal grooves usually number lh, the trunk vertebrae

15. Vomerine teeth range from 5 to 12 in a series. Of 15 specimens
examined, the largest is 56 mm. in snout-vent length.


Plethodon vandykei larselli Burns
Plethodon vandykei larselli Bums (19h4: 83-7).





- 38 -


Type:- USNM 1Jh129, an adult male, collected on the north slope of
Larch Mountain, three miles from the summit on the Multnomah Falls

Trail, Multnomah County, Oregon, on May 24, 1953, by Douglas M. Burns.

Diagnosist- A race of Plethodon vandykei in which the ventral color is

cardinal red to reddish orange.

Range:- Known only from the type locality and from Archer Falls, Ska-

mania County, Uashington (figure 4).

Description:- Specimens of this subspecies have not been examined and

reference should be made to the original description for details of

structure and coloration.



Plethodon vehiculum Group

Plethodon dunni Bishop

Plethodon dunni Bishop (1934: 169). Jewett (1936: 71). Fitch (1936:

637-8). Graf, Jewett, and Gordon (1939: 102). Gordon (1939: 55-6).

Slater (1939: 154). Bishop (1943: 242-6). Stebbins (1951: 68-72).

Stebbins (1954: 54-5). Storm (1955: 64-5). Dumas (1955: 65).

Slater (1955: 132).

Type:- USNM 95196, an adult female, collected just outside the city

limits of Portland, Clackanas County, Oregon, by Stanley G. Jewett, Jr.,

on January 13, 1934.

Diagnosis:- A Western Plethodon with 16 trunk vertebrae.

Range:- Curry County, in southeastern Oregon, north to Pacific County,






- 39 -


Washington, east to the western slope of the Cascade fountains (figure

5).

Description:- The dorsal stripe is made up of yellowish green lipo-

phores. This pigment also occurs in abundance on the sides, but is re-

duced on the belly. On the lower sides and belly there are a few

yellowish guanophores., There are brassy guanophores in the iris.


The costal grooves usually number 15, the trunk vertebrae 16.

The medial end of the vomerine series projects posteriorly toward the

parasphenoid patches, so that the two vomerine series form a V. Vomer-

ine teeth range from 4 to 13 in a series. The largest specimen examined

is 65 mm. in snout-vent length.


P. dunni is closely related to P. vehiculum, but differs in

size, coloration, number of vomerine teeth and number of body segments.

It occurs from southwestern Washington south through coastal Oregon.

This species occurs sympatrically with P. vandykei in southwestern Wash-

ington, with P. products in southwestern Oregon, end with P. vehiculum

throughout most of its range.


P. dunni is apparently the most aquatic Plethodon. Stebbins

(1951: 70) states that it is almost invariably found in places that are

saturated with water, and that it will often take to the water in an

attempt to escape capture.


Most individuals possess a dorsal stripe that is greenish

yellow in color, but Stebbins (1951: 69) reports that nelanistic speci-

mens lacking the dorsal stripe have been found in Bcnton County, Oregon.






- hO -


S. 0o 0o








Figure 5. The distribution of Plethodon dunni in Oregon and south-
western V'ashing'mn.






- 41-


Plethodon vehiculum (Cooper)
Ambystoma vehiculum Cooper (1860: pl. 31, fig. 4).
Plethodon intermedius Baird (in Cope, 1867: 209). Cope (1869: 100).
Strauch (1870: 72). Boulenger (1882: 57). Cope (1883: 23).
Garman (1884: 38). Cope (1889: 15l-7). Cox (1907: 52). Van
Denburgh (1916: 218-9). Fowler and Dunn (1917: 25). Hardy
(1926: 22). Kermode (1926: 35). Dunn (1926: 154-6). Slevin
(1928: 52-5). Logier (1932: 317-8). Slater (1933: i4). Svihla
(1933: 39). Slater (1934: 1l0-1). Slevin (1934: 46). Cowan
(1937: 18).
Plethodon vehiculus (Cooper). Bishop (1934: 171). Jewett (1936: 71).
Watney (1938: 89). Slater (1939: 154). Graf, Jewett, and Gordon
(1939: 10-1). Brown and Slater (1939: 9).
Plethodon vehiculum (Cooper). Slater (190L: 43). Slater and Brown
(1941: 75-7). Bishop (1913: 278-81). Stebbins (1951: 84-7).
Stebbins (1954: 57-9). Logier and Toner (1955: 17). Slater

(1955: 133-4).

Type:- Apparently no longer in existence. The type locality is Astoria,
Oregon.

Diagnosis:- A Western Plethodon with 17 trunk vertebrae.

Range:- From Coos County, in southwestern Oregon, north to southwestern
British Columbia, including Vancouver Island (figure 6).

Description:- Lipophores in the region of the dorsal stripe may be ab-

sent, producing a uniformly colored phase, or present, resulting in a






















































Figure 6. The distribution of Plethodon vehiculum in Oregon, Wash-

ington, and British Columbia.


- 2 -






- 43 -


striped phase. The color of the dorsal stripe is quite variable, vary-

ing from light yellow, through yellow, orange, and red to brown. The

lipophores are absent from the sides, but are present on the belly. The

sides are black with only a few small white guanophore spots. These are

also present on the belly, and along with the melanophore and lipophore

pigmentation give it a mottled appearance. Small white guanophore spots

similar to those on the sides, as well as smaller brassy flecks, are

present on the dorsum of the dark phase individuals. Brassy guanophores

are present in the iris.


Costal grooves usually number 16, trunk vertebrae 17. Vomer-

ine teeth range from 3 to 7 in a series and the two series converge

posteriorly to form a V as in dunni. The largest specimen 49 examined

is 51 mn. in snout-vent length.

This species is the smallest Western Plethodon and has the

largest range. It is the most abundant Plethoden over most of its

range. P. vehiculum is superficially quite similar in appearance to

the eastern P. cinereus. Dark and striped phases are present and the

belly is mottled in both species. The similarities between the two are

probably due to convergence or parallel evolution because in all other

characters, P. vehiculum is morphologically more similar to the other

Western Plethodons.


Plethodon products Group


Plethodon products, new name

Plethodon elongatus Van Denburgh (1916: 216-8). (non) Salamandra elon-

gata Valenciennes in Dumeril and Bibron (1854: 84). Grinnell and









Camp (1917: 134). Storer (1925: 21, 10). Dunn (1926: 156-8).

Slevin (1928: 55-7). Slevin (1934: 46-53). Wood (1934: 191).

Fitch (1936: 638). Wood (1939: 110). Gordon (1939: 13, 30, 56).

Bishop (1943: 246-9). Hilton (1946: 45). Stebbins and Reynolds

(1947: 41-2). Stebbins (1951: 72-6). Stebbins (1954: 55-6).

Type:- CAS 29096, collected at Requa, Del Norte County, California, by
J. R. Slevin, May 22-26, 1911.

Diagnosis:- A Western Plethodan with 19 trunk vertebrae.

Range:- Southwestern Oregon and northwestern California (figure 7).

Description:- The belly of this species is very dark with a few sact-

tered white guanophore spots. The orange to reddish brown dorsal lipo-

phore stripe is usually brighter in juveniles than in adults, where it

is often reduced or absent. Often it is divided into a right and left

dorsolateral stripe by the presence of medial melanophore pigment.

The costal grooves usually number 18, the trunk vertebrae 19.

Vomerine teeth range from 4 to 7 in a series. This is a large species,

the largest of 18 specimens examined is 66 mn. in snout-vent length.

This is the most elongate of the Western Plethodons in the

Pacific Northwest. Its greater number of body segments distinguishes

it from the species vanXkei, dunni, and vehiculum, and its webbed toes

also distinguish it from the last two. It is probably more closely re-

lated to P. neomexicanus than the other Western Plethodons. P. products
has a rather limited distribution. It is known only from Trinity, Hum-

boldt, and Del Norto Counties, C'lifornia; and Curry County, Oregon.



































Figure 7. The distribution of Plethodon products in California and

Oregon.


The distribution of Plethodon neomexicanus in New .ecxico.


- 45 -


Figure 8.








- 46 -


Stebbins (1951: 76) believes that specimens from the interior of the

range differ in several respects from those on the coast.

Van Denburgh described this species in 1916, apparently with-

out realizing that the name he proposed, elongatus, was a junior homo-

nym of Salamandra elongata Valenciennes (in Dumeril and Bibron, 1854:

84) (= Flethodon glutinosus). This is a primary homonym due to the

fact that the name elongata is available for Plethodon glutinosus, al-

though the combination Plethodon elongatus has never been used for the

slirr salamander. No subsequent worker has proposed a new name to re-

place the preoccupied name of the Del Norte salamander and it has al-

ways been referred to as Plethodon elongatus. This species has been

known by the name elongatus since 1916 and it is unfortunate that the

name has to be changed, but there is no alternative than to propose a

new name in place of the preoccupied elongatus. The name products

also refers to the elongated condition of this species.


Plethodon neomexicanus Group


Plethodon neomexicanus Stebbins and Riemer

Eurycea multiplicata (Cope). Dunn (1926: 312-4, part).

Plethodon neomexicanus Stebbins and Riemer (1950: 73-80). Stebbins

(1951: 76-9). Stebbins (1954: 58).


Type:- MVZ 49033, an adult male, collected 12 miles west and 4 miles
south of Los Alamos, Sandoval County, New I'xico, at an altitude of

about 8750 feet, by Robert Stebbins, on August 14, 1949.


Diagnosis:- A western Plethodon with 20 trunk vertebrae.






- 47 -


Range:- Known only from the vicinity of the type locality in the Jemez

Mountains of New Mexico, (figure 8).


Description:- This species has not been examined in life and reference

should be made to the original description for an account of the pig-

mentation.

Costal grooves are usually 19, trunk vertebrae 20. Vomerine

teeth range from 4 to 11 in a series in the 7 specimens examined. This

is a large species, the type is over 70 mE. in snout-vent length. Ac-

cording to the data listed in Stebbins and Riemer (1950: 75), sexual

maturity is not reached until approximately 50 m~. in snout-vent length.


This is an elongated salamander, with the largest number of

trunk vertebrae of any of the western forms. It is unusual in that most

specimens have only one phalanx on the fifth toe of the hind limb in-

stead of the usual two phalanges. This is probably an intermediate

stage in the loss of the fifth toe and reduction to the four-toed con-

dition Iknown to have occurred in several unrelated salamander genera.


The dorsal stripe is apparently absent in adults, but present

in juveniles. This form is unique among the western Plethodons in lack-

ing the striped phase in the adult, and also in possessing a large num-

ber of brassy guanophores on the dorsum.



The Eastern Small Plethodons


The Eastern Small Plethodons are characterized by their small

size. Except for P. welleri, they possess a higher number of trunk

vertebrae and are relatively more elongate than the Eastern Large









Plethodons. Four species are included in this group. P. welleri has

a restricted range, and is known only front a few counties in north-

western North Carolina and adjacent Tennessee and Virginia. P. rich-

mondi is a polytypic form with three described races, and probably

others which have not yet been defined. Its range centers in the

Appalachian Plateaus Physiographic Province and it also occurs in im-

mediately adjoining areas of several adjoining Provinces. P. cinereus,

with three subspecies, has the widest range of any Eastern Small Pleth-

odon, occurring over most of eastern United States and southeastern

Canada, except in the region occupied by P. dorsalis. The range of

P. dorsalis is centered in the Interior Low Plateaus Physiographic

Province. P. d. angusticlavius is here regarded as a subspecies of

dorsalis, rather than of cinereus, as originally described by Grobman

(19h4: 302).


The four species form a natural group of closely related forms.

All possess webLed toes, a pigmented poritoneumJ, lowi vomerino tooth

counts, brassy flecks on the dorsum, and white guanophore spots on the

belly and sides. Two species, cinereus and dorsalis, are more similar

to each other than either is to welleri or richmondi. Both cinereus

and dorsalis typically possess at least as much white as black pigment

on their bellies, and both are characterized by the presence of a red-

backed phase in which there is a dorsal band of red or yellow lipophore

pigmentation on the dorsum of the body and tail. In richmondi and

welleri, the white pigment on the belly is limited to small spots and

there is a much greater amount of black pigment than vhite. The red-

bicked phase, present in all of the races of dorsalis and cinereus,


- h8 -







- 49 -


is always absent in richmondi and welleri.


P. r. richmondi is the largest form, and also possesses the

greatest number of trunk vertebrae, but both size and number of ver-

tebrae are slightly reduced in the race popei, and decrease still more

in the subspecies netting. Geographic variation in the number of

trunk vertebrae is most pronounced in this species, with a range of

18 to 24 in all of the subspecies. P. welleri is less elongate and has

fewer vertebrae than other small eastern species. It is unusual in its

possession of ovarian eggs pigmented with melanophores, as well as in

having an extremely dark parietal peritoneum. The brassy flecks on

the dorsum of welleri are concentrated to form large patches, giving it

a unique appearance not found in any other Plethodon. Its nearest rel-

ative is probably P. r. netting, but welleri is closest geographically

to P. r. popei.


In most of their ranges, cinereus and dorsalis are allopatric

forms, but in several areas where their ranges meet, there are records

of the two occurring together in the same locality (see below). In

each of these instances, there is no good evidence for hybridization or

intergradation between the two forms, and for this reason they are

usually considered as distinct species. They differ in several pig-

mentation characters, as well as in the average number of trunk ver-

tebrae and the shape of the mental gland in adult males. P. d~.rsalis

usually has 19 trunk vertebrae (range 18-20). Two races of cinereus

typically have 20 trunk vertebrae (occasionally 19 or 21), while the

third subspecies (polycentratus) usually has 21 or 22 (rarely 23)

trunk vertebrae. In all of the Eastern Small Plethodons except dorsalis,









the mental gland is rather poorly developed and difficult to differen-

tiate (except, perhaps, during the breeding season) from the adjacent

portion of the chin. In dorsalis, on the other hand, it is a distinct

rounded elevated gland, as in the Eastern Large Plethodons. Dunn (1926:

24) suggests that the striped pattern or dorsalis is more primitive than

that of cinereus, since the paired red dorsal spots of several primitive

plethodontids might be expected to pass through a zig-zag striped phase

similar to that of dorsalis before evolving into a uniformly straight-

edged stripe.


In 19L4, Grobman described the narrow-striped populations oc-

curring in southwestern Missouri and northwestern Arkansas as a distinct

subspecies, Flethodon cinereus angusticlavius. This form possesses sev-

eral characteristics that appear to link it more closely with dorsalis

than with cinereus. It usually has 19 trunk vertebrae, as in dorsalis,

while cinereus populations to the northeast and south of the range of

angusticlavius usually have 20 trunk vertebrae. The mental gland is of

the dorsalis type and in some specimens the dorsal stripe has irregular

edges anteriorly, resembling very closely the pattern in dorsalis.

Living specimens of angusticlavius have not been examined, so no accur-

ate information is available on pigmentation characters, but the other

characters strongly suggest that angusticlavius should be linked sub-

specifically with dorsalis rather than cinereus.


The elongation and increased number of trunk vertebrae in P.

r. richmondi, P. r. popei, and P. c. polycentratus would appear to be

a marked specialization of the usual plethodontid type. The forms

welleri and dorsalis would appear to have retained more primitive char-


- 5C -






- 51 -


acteristics, but both have probably changed considerably from their

common ancestor. The relationships of the Eastern Small Plethodons

would appear to be best indicated by the phylogeny outlined in figure

9.

Plethodon welleri Group


Plethodon welleri Walker

Plethodon welleri Walker (1931: 48-51). Walker (1934: 190). Bishop

(1943: 285-7). Grobnan (19h4: 313). Snyder (1946: 174). Hoff-

man and Kleinpeter (1948a: 107). Hoffman (1953: 86-7).


Type:- USNM 84135, an adult male, collected on Grandfather mountain at
an altitude above 5000 feet, near Linville, North Carolina, by W. H.

Weller and Ralph Dury, on August 27, 1930.


Diagnosis:- A dark-bellied, Eastern Small Plethodon with 17 trunk ver-

tebrae and abundant dorsal brassy spotting.


Range:- From Yancey County, North Carolina, northeast in Tennessee

and North Carolina to Mt. Rogers and Vhite Top Mountain, Virginia (fig-

ure 10).


Description:- The dorsal pattern consists of large anastomosing patches

of brassy guanophore spots. These spots appear to consist almost en-

tirely of brassy guanophores, the white type of guanophore pigmentation

present on the sides of welleri and on the dorsum of most plethodons, is

not evident on the back of welleri. The brassy pigment is more concen-

trated than in any other form and the appearance of the dorsal spots is

similar to the large white spots of glutinosus, except for the color,





- 52 -


cinerous serrotus popei
polycentrotus ongusticlovius dorsolis richmondi nettingi



cinereus dorsolls
richmondi















Figure 9. Suggested phylogeny of the Eastern Small Plethodons.


Figure 10. The distribution of Plethodon welleri in North

Tennessee, and Virginia.


Carolina,










which is brassy. Small white spots (0.1-0.2 am.) are scattered over the

belly and are similar to those of P. r. popei. The lateral spots (up to

1 mm. in diameter) are white with a slight amount of brassy flecking.

The costal grooves usually number 16, the trunk vertebrae 17.

Vomerine teeth range from 2 to 7 in a series. In the 39 specimens ex-

amined, maximum known snout-vent length is between 45 and 50 am. Sexual

maturity is reached at about 35 mm. in snout-vent length.


P. welleri is the least elongate of all of the Eastern Small

Plethodons, with the same number of trunk vertebrae (17) as in most of

the Eastern Large Plethodons. In body build it resembles the large

forms more than any other Eastern Small Plethodon. Its small size, ver-

tebral structure, webbed toes, and pigmentation characters would appear

to associate it more closely with the other small eastern forms.


This species has long been believed to be restricted to high

elevations and was recorded only from Flat Top Mountain and Grandfather

Mountain, North Carolina; and Mt. Rogers and ihite Top Mountain, Virgihia.

Recently, Hoffman (1953: 86) collected the species at an elevation of

2500 feet in Johnson County, Tennessee. I visited this locality during

the summer of 1955, and although conditions were very dry, succeeded in

collecting one young specimen, thus confirming Hoffman's record. This

species may well occur in suitable habitats at low altitudes throughout

the region.


Walker (1934: 190) has pointed out that individuals from YVhite

Top Mountain, Virginia, possess more spots on their venters than indivi-

duals from the type locality, Grandfather Mountain, North Carolina.


- 53 -









Specimens from Mt. Rogers (USNM 124h21-9) also possess spotted bellies.

One specimen from Flat Top Mountain, Yancey County, reported by Snyder

(1946: 174) is also described as having a more conspicuous mottling on

the venter. Perhaps the Grandfather Mountain population is unusual in

lacking this characteristic. The low altitude specimen from Tennessee

has a greater amount of dorsal brassy pigment than eight living topo-

types from Grandfather Mountain. I have not examined living specimens

from any of the other localities.


P. welleri is unusual in possessing dark ovarian eggs that

are pigmented with nelanophores. Its closest relative is probably P.

richmondi, which it resembles by the presence of a dark belly. P. r.

nettingi usually has 19 trunk vertebrae, although occasional specimens

possess 18 or 20. Since a small percentage of welleri also have 18

trunk vertebrae (table II), there is slight morphological overlap be-

tween the two forms in this character.


TABLE II

THE NUMBER OF TRUNK VERTFERAE IN GEOGMRPHIC SAMPLES OF PLETHODON WELLERI

Number of trunk vertebrae
Locality
16 17 18

Grandfather Mountain, North Carolina 25

Johnson County, Tennessee 1

White Top Mountain, Virginia 4

Mt. Rogers, Virginia 1 6 2


-S5 -










Plethodon richmondi


In 1938, two new Eastern Small Plethodons, P. richmondi and

P. nettingi, were described by Netting and Mittleman (1938: 297) and

Green (1938: 295). Both are characterized by their dark bellies and

brassy dorsal flecking. Available samples of richmondi from Ohio and

West Virginia possess 20 to 22 costal grooves (21 to 23 trunk vertebrae),

while P. netting has 17 to 19 costal grooves (18 to 20 trunk vertebrae).

They both differ from P. c. cinereus in the number of vertebrae, and they

are distinguished from the entire cinereus group by their dark bellies

and lack of red pigment. Most previous writers are in agreement that

these two forms, richmondi and nettingi, are more closely related to

each other, and to welleri, than they are to cinereus and dorsalis

(Netting and Mittleman, 1938: 292; Green: 1938: 298; Grobman, 1944: 311).


In 1949, Grobman described another flAcked plethodon (P. hul-

dae) which he assigned to this group because of its heavily flecked

dorsum. This form possesses 20 trunk vertebrae, the same as cinereus,

and also has a mottled belly as in cinereus. Rabb (1995: 261-3) and

Muchmore (1955: 170-2) present convincing evidence that huldae, although

possessing brassy dorsal flecks similar to those of richmondi and net-

tingi, is actually based on dark-phase specimens of P. cinereus. Much-

more (1955: 172) goes so far as to state that "since P. c. cinereus

possesses brassy flecks on the dorsum and since P. huldae can no longer

be considered valid, it is certainly desirable that the concept of a

welleri group of Plethodon distinct from a cinereus group be abandoned."

Obviously these forms are all more closely related than any of than are

to the Eastern Large Plethodons or the Western Plethodons, yet the fail-


- 55 -









ure of one suggested character to define the group should have no bear-

ing on the fact that other features are useful in distinguishing it

(dark belly and lack of red dorsal stripe).


Netting and Mittlemau (1938: 292) state that specimens of P.

richmondi from Watauga County, North Carolina, differ from typical

richmondi, but do not give any evidence to support this contention.

Neither Bishop (1943: 239) nor Grobman (19lh: 312) include this locality

in their distribution maps of the range of richmondi, although Grobman

mentions the literature reference to the North Carolina specimens. More

recently, Hoffman and Hubricht (1954: 192) report richmondi from several

localities in southwestern Virginia and northwestern North Carolina, but

do not find any consistent differences between these specimens and topo-

types of richmondi. A study of their material and large series from this

area in the University of Florida Collection have shown, however, that

these southern richmondi are actually quite distinct in the number of

trunk vertebrae from more northern richmondi. This southern form has

recently been described as a new subspecies of richmondi, P. r. popei,

by Highton and Grobman (in press). No other character could be found

to distinguish preserved specimens of popei and richmondi. Living

specimens of P. r. richmondi have not been available during this study,

so it has not been possible to compare the pigmentation characters of

the two forms.


On the basis of the slight overlap in distinguishing charac-

ters, as well as the geographic replacement of the three forms, rich-

mondi, popei, and netting, Highton and Grobman (in press) suggested

that they should all be considered subspecifically related. One


- 56 -










matter, not discussed in their paper, is the apparent sympatric rela-

tionship of netting and richmondi. Although the two forms, to my

knowledge, have not been collected at the same locality, the entire

range of netting, as summarized by Brooks (1948), is surrounded by

records of richmondi.


Thurow (1955) has recently reported netting from Bedford

County, Virginia, a locality about equidistant from the nearest known

netting and popei localities. An examination of these specimens

(CNHM 60512-8) confirms Thurow's suggestion that they belong to this

group. Although they are poorly preserved, their dark bellies indi-

cate that they are not dark-phase cinereus. They differ from both

netting and pope, however, in costal groove count. Five of the seven

specimens have 19 costal grooves, while the other two have 18. The sam-

ple is small, but the probability that they were taken from a popula-

tion of netting similar to that in Randolph and Pocahontas Counties,

West Virginia, which has 19 costal grooves less than 5% of the time, is

very low. Four of the seven Bedford County, Virginia, specimens have

20 trunk vertebrae, two possess 19, and the remaining specimen is too

small to obtain an accurate count from the radiograph, but it probably

also has 20 trunk vertebrae, since it has 19 costal grooves. The pop-

ulation from which these specimens were collected probably represents

an intermediate one between pope and netting. If the usual number of

trunk vertebrae is 20, and this occurs with high frequency, this popu-

lation should probably be given separate subspecific nomenclatorial

status. At present, with only seven poorly preserved specimens avail-

able, too little is known of its variation to described it as new here.

Its importance lies in the fact that an intermediate population, often


- 57 -






- 58 -


possessing 20 trunk vertebrae, is known from a locality between the

ranges of netting (usually with 19 trunk vertebrae) and popei (usually

with 21 trunk vertebrae). This may be considered further evidence that

nettingi and popei are subspecifically related.


In the Valley and Ridge Province of Virginia, there exists a

population of P. r. richmondi which Hoffman and Hubricht (1954: 192)

believe to be different in both color and structural features from

other populations of P. richmondi. They do not state the ways in which

it differs, but an examination of preserved specimens from this region

(Alleghany and Rockingham Counties, Virginia) indicates that these

animals, although possessing a vertebral count similar to richmondi,

differ from it in having a mottled belly. Specimens from these coun-

ties are easily segregated from topotypical richmondi and ppei on the

basis of the character of the belly. In ten specimens of the mottled

bellied form for which vertebral counts are available, six possess 22,

three 23, and one 24 trunk vertebrae. The average is slightly higher

than the usual richmondi number, but does not differ significantly

from it. It is quite likely that examination of living specimens, and

the accumulation of more data on vertebral counts may reveal differ-

ences which will indicate that this population represents a distinct

nominal form. Specimens from other areas in the Valley and Ridge

Province should be studied in order to delimit the range of the mottled-

bellied richmondi.


The distribution of these forms indicates that there is

probably a series of five races, two of them undescribed, each of which

replaces its nearest relative geographically. One extre-" (nottingi)

occurs sympatrically with the two at the other extreme (richmondi and










the undescribed Virginia Valley and Ridge animal). Table III shows the

variation in the vertebral counts of these populations.


TABLE III


GEOGRAPHIC VARIATION IN THE NUMBER OF TRUNK VERTEBRAE IN PLETHODON

RICHMONDI


Number of trunk vertebrae
Sample
18 19 20 21 22 23 24 Mean

P. r. netting 1 22 1 19.0

Bedford County, Virginia 2 4 19.7

P. r. opei 4 51 12 21.1

P. r. richmondi 4 30 9 22.1

Alleghany and Rockingham 6 3 1 22.5
Counties, Virginia




The races of richmondi appear to form a ring of subspecies,

none of which is completely distinct morphologically from the related

adjacent forn (or forms). P. r. netting is not known below 3550 feet

elevation in the Cheat Mountains of West Virginia (Brooks, 1948) and

it thus may be completely isolated ecologically from P. r. richmondi.

There is no information on the upper altitudinal limits of richmondi

in the literature, but it is known from localities throughout most of

West Virginia. A similar case has been reported by Stebbins (1949) for
the western salarrander genus Ensatina, in which the two end forms of an

allopatric series of subspecies occur in immediately adjacent regions


- $9 -





- 60 -


without any evidence of interbreeding. An accurate knowledge of the 0-

cological distribution of the overlapping forms of P. richmondi is lack-

ing. There appears to be little or no overlap between the two terminal

races of Ensatina eschscholtzi, whereas in this case, one nettingg)

definitely occurs within the range of richmondi, for there are records

of the latter to the north of the Cheat Mountains in Pennsylvania, to

the east and weat in West Virginia, and to the south in Virginia.


In these series of populations we probably see the stages

through which the subspecies of richmondi have differentiated. All of

the forms probably have changed somewhat from the original stock, but

the close similarity of all the forms, except for the number of body

segments, would seem to indicate that this change has not been great.

It is difficult to determine v.hich form most closely resembles the an-

cestral condition. P. r. richmondi is unlike most plethodons in its

elongate form and would appear highly specialized. On the other hand,

it wide distribution and the fact that the eastern Valley and Ridge

population has a mottled belly, approaching that of the cinereus group,

might be considered evidence that this form is a more primitive gener-

alized animal. It is possible to reconcile these viewpoints, for it

is often found that a given form is specialized in some ways, yet re-

tains certain other primitive characteristics.


Since P. r. netting is apparently limited to high altitudes

in the Cheat Mountains, it could be interpreted either as a specialized

type adapted to this habitat, or as a relict of a once more widely dis-

tributed spruce forest population. At present, the evidence is not

sufficient to choose between the two alternatives. On the basis of its






- 61 -


fwer trunk vertebrae, netting would appear to be less specialized

than the other subspecies.

Intergradntion between the races of richmondi my occur in

certain regions. P. r. netting may now be completely isolated from

its nearest relative, but the ranges of popei and richondi probably

meet in eastern Kentucky, and intergradation riuht be expected. La-rg

samples from critical areas will be necessary before conclusive evi-

dence is obtained, since intergrades between popei and richfendi, for

example, would be expected to possess about an equal number of specimens
with 21 and 22 trunk vertebrae. Large series of specimens from each

county in and on both sides of the area of intcrgradation would be nne-

cscsry to determine its extent. Such series are not now available

from Kentucky, and hollow symbols representing literature records for

this region on the distribution map (figure 11), my represent popei,

intergradient, or richmondi populations,


Plethodon richnondi richmondi netting and Dittleman

Plethodon richmondi Notting and Mittleman (1938: 287). -:ettinC (1939:

50-1). Dury and Geesing (1940s 31). Bishop (1943: 272-5). Grob-

man (1944: 312). Wood (1945a: L 9). Wood (19LSb: 206-10). Getting
(19t6: 12). Wood (1946: 169). "ood and Duellran (1947: 3). Grob-

man (19b9: 135). -ichmiond (1952: 314). Green .and Walker (1954:

60). Duellman (195h: L0-5). HIoffman and Hubricht (1954k 191-3).
Plethodon richmordi richmoridi Netting and Uittleman. Highton and Grob-

man (in press).

Type:- CM 1189, an adult mle, collected in hitterr Park, Luntington,






- 62 -


Cabell County, West Virginia, at an elevation of 600-700 feet, by Neil

D. Richmond and N. Bayard Green, on October 15, 1938.

Diagnosis:- A dark-bellied Eastern Small Plethodon, usually with 22

trunk vertebrae (range 21-24), which completely lacks red pigment.

Range:- From Centre County, Pennsylvania, south through western Mary-

land, West Virginia, and northwestern Virginia, west to northeastern

Kentucky, and north to southern and eastern Ohio (figure 11).

Description:- This form has not been examined in life and nothing on

the pigmentation can be added to previously published accounts.

The costal grooves usually number 21, the trunk vertebrae 22.

Vomerine teeth range from 3 to 9 in a series. This is the largest

Eastern Small Plethodon, the largest specimen examined, from Alleghany

County, Virginia, is 60 am. in snout-vent length.


Plethodon richmondi popei Highton and Grobman

Plethodon richaondi Netting and Mittleman. Barbour (1953: 85-6).

Hoffman and Hubricht (1954: 191-3).

Plethodon richmondi popei Highton and Grobman (in press).

Iype:- UF 8226, a maturing male, collected at Comers Rock, Grayson-

Wythe County line, Virginia, by Arnold B. Grobman and Marc R. Grobman,

on August 5, 1955.


Diagnosis:- A race of Plethodon richmondi that usually possesses 21

trunk vertebrae (range 20-22).


RanEt- Known from Harlan County, Kentucky; Tazewell, Smyth, Grayson,






- 63 -


Figure 11. The distribution of the subspecies of Plethodon richmondi,

Solid symbols represent localities from vw Lch specimens have

been examined. Hollow symbols, represent literature records.






- 61 -


and ythe Counties, Virginia; and Ashe, Alleghany, and Watauga Counties,

North Carolina (figure 11). This form may have a greater range than

now known. Specimens from adjacent Kentucky and Kest Virginia have not

been examined. They may also belong to this race.

Description:- Living specimens possess both types of guanophore spots

on the dorsum. Small brassy flecks are very abundant and larger white

spots are also present. On the sides and venter there are larger white

or yellow spots.

The costal grooves usually number 20, the trunk vertebrae 21.

Vomerine teeth range from 3 to 8 in a series. The largest specimen ex-

amined is 48 mm. in snout-vent length. Sexual maturity is reached be-

tween 35 and h5 mm. in snout-vent length.


Plethodon richmondi netting Green

Plethodon netting Green (1938: 295-9). Bishop (1943: 266-9). Grobman

(19bh: 313). Brooks (1945: 231). Brooks (1948: 239-44).
Plethodon richmondi nettingi Green. Highton and Grobman (in press).


Type:- CM 10279, an adult male, collected on Barton Knob, near Cheat
Bridge, Randolph County, West Virginia, at an elevation of about L000

feet, by M. Graham Netting, on June 29, 1935.

Diagnosis:- A race of Plethodon richmondi that usually possesses 19 trunk

vertebrae (range 18-20).

Range:- Known from altitudes above 3500 feet in the Cheat Mountains of

Randolph and Pocahontas Counties, West Virginia (figure 11).






- 65 -


Description:- In life, the dorsum of this form is similar in colora-

tion to P. r. popei. The costal grooves usually number 18, the trunk

vertebrae 19. Vomerine teeth range from 3 to 8 in a series. The

largest specimen examined is h5 mm. in snout-vent length. This form

appears to have a smaller average size than the other races of rich-

mondi. Sexual maturity is reached at about 35 mm. in snout-vent length.


Plethodon cinereus Group


Plethodon dorsalis

The range of P. dorsalis centers in the Interior Low Plateaus

Physiographic Province, but does not appear to be restricted to it, for

records are available from several adjacent provinces. This species has

not heretofore been recorded from Georgia, but specimens are now avail-

able from four different localities in that state, three of which are

in the Piedmont Province. The southernmost record is from Upson County

(UIPZ 8557h), only a few miles above the Fall Line. Other records are

for Henry County (UF 8371 (3), UF 8413 (3)); Cobb County (UG 206 (6);

UG 275 (36)); and Dade County (ERA-JTN 12128 (12)). Probably the nat-

ural range of this form includes the western part of the state above

the Fall Line.


The sympatric occurrence of this species with P. cinereus in

Georgia, Tennessee, Indiana, Illinois, and Oklahoma will be discussed

below. The two forms are very similar in appearance, and it is often

difficult to identify individual specimens. For this reason a detailed

study of the two species in the areas of overlap will be necessary be-






- 66 -


fore it can be determined whether or not hybridization occurs.


In Georgia, where there is no overlap in the vertebral counts

of the two species, it is impossible, on other grounds, to identify a

small percentage of the available specimens. There are, however, sev-

eral differences between the two species in Georgia that are apparent

in a large majority of the available specimens. These include the shape

of the mental gland in adult males; the zig-zag stripe of dorsalis, com-

pared to the straight-edged stripe in cinereus; the presence of more red

pigment in front of the eyes on the head of dorsalis; the great reduction

in amount of melanophore pigmentation on the belly of dorsalis; and a

similar reduction in red lipophore pigmentation on the belly of cinereus.

The fact that there are a few exceptions to each of these species char-

acteristics might be considered evidence for hybridization were it not

for the fact that occasional specimens of each species from localities

in which the other form is absent show at least some of the same varia-

tions from the usual pattern. The fact that there is no tendency toward

an increase in the number of trunk vertebrae in Georgia dorsalis popula-

tions is also significant (see table IV). It may be seen from this table

that there is no strong tendency for an increase in the number of verte-

brae in samples of dorsalis that are from areas in which geographic over-

lap with cinereus occurs. We may conclude that there is, as yet, no

good evidence for hybridization between the two species, but that more

study is needed in all of the areas in which the two occur together.


There are no available records of dorsalis in southeastern

Missouri. This region should be explored in order to determine whether

or not dorsalis or angusticlavius are present. Smith (1918: 1) has






- 67 -


recently reported dorsalis from several localities in southeastern

Illinois.


TABLE IV

THE NUMBER OF TRUNK VERTEBRAE IN SAMPLESOF PLET]HDON DORSALIS


Number of trunk vertebrae
Sample
Same 18 19 20


P. d. dorsalis

Georgia* 2 49 2

Alabama 2

Tennessee

Great Smoky Mountains* 34 9

Van Buren County 1 h4 6

Marion County 2

Indiana 1 2

P. d. angusticlavius

Arkansas 23 5

Areas in which cinereus and dorsalis have been taken together at the
same locality.


Dunn (1926: 162) states that the unstriped phase in dorsalis

is confined to adults and that this phase is much lighter than the dark

phase of cinereus. The latter part of his statement appears to be true,

but in a series of 31 living specimens of dorsalis from Van Buren County,

Tennessee (UF 8394), there are five juveniles (16 to 18 mm. snout-vent

length) that are definitely of the dark phase. As in adults, there is






- 68 -


a slight amount of red pigment in the region of the back in which the

stripe is located in red-backed individuals, so that an outline of the

irregular stripe can be seen when held at a certain angle to the light.

The presence of the red pigment, as well as a reduction in the melano-

phore pigmentation does give the lead-backed phase of dorsalis a lighter

appearance than the corresponding phase of cinareus.

Grobman (19i4: 308) presents evidence to show that Baird

should be credited with the authorship of the name dorsalis. Under
Article 21 of the International Rules of Zoolcgical Nomenclature as

of 19h4, he was correct. Since 194h, however, the Rules have been
amended, so that Cope should now be recognized as responsible for this

name.


Plethodon dorsalis dorsalis Cope

Plethodon cinereus dorsalis Cope (1889: 138-9). Blanchard (1926: 368-9).

Bishop (19N3: 236-9). Parker (1948: 22). Chermock (1952: 29).

Plethodon erythronotus (Green). Garman (1894: 38).

Plethodon dorsalis Cope. Stejneger and Barbour (1917: 15). Dunn (1918:

460-2). Dunn (1926: 158-62). Mohr (1937: 4h). Parker (1937: 631
Parker (1939: 75). King (1939: 550-1). Swanson (1939: 687).

Grobman (1944: 308-11). Smith (1.9h8: 1). Sinclair (1950: 50).

Mohr (1952: 59-60). Throw (1955: 62-3). Holman (1955:' 13).

Type;- USNM 3776, collected at Louisville, Jefferson County, Kentucky.

Diagnosis:- An Eastern Small Plethodon with the usual number of trunk

vArtebrae 19 (range 18-20), and a red dorsal stripe with irregular edges






- 69 -


in the red-backed phase.


Range:- From southern Illinois, Indiana, and southeastern Ohio, south

through Kentucky and Tennessee to northern Alabama and northwestern

Georgia (figure 12).


Description:- The dorsum of both color phases of P. d. dorsalis has

small white spots (0.2-0.4 mm.) as well as smaller brassy flecks. The

red-backed phase, in addition to the other pigments, contains a large

amount of red lipophore pigment. All of these chromatophores appear

to be identical with those of P. cinereus. The main difference between

the two species is in the abundance and distribution of the pigments.

The melanophore background in dorsalis is somewhat reduced, giving the

animal an overall lighter appearance than cinereus. The melanophore

pigment on the belly of dorsalis is greatly reduced with a corresponding

increase in the amount of red lipophores, so that the belly appears to

be mottled with red and white rather than black and white, as in ciner-

eus. In dorsalis there is a concentration of red pigment on the head

in front of the eyes. The lateral guanophore pigment is often yellowish

in color. The dorsal red stripe is quite variable. In some specimens

the edges are irregular for the entire length of the body, while in

others, they are irregular only in the anterior half or third of the

body. Tho latter condition is especially common in Georgia specimens,

and occasional specimens from Georgia have straight-edged dorsal stripes

as in cinereus. Specimens with straight-edged dorsal stripes have been

reported also from Indiana (Blanchard, 1926: 369) and Tennessee (Grob-

man, 1944: 309-10).






- 70 -


Figure 12. The distribution of the subspecies of Plethodon dorsalis.






- 71 -


The costal grooves usually number 18, the trunk vertebrae

19. Vomerine teeth range from 3 to 6 in a series. This is a small

species; sexual maturity is probably reached at about 30 mm. in snout-

vent length. The largest specimen examined is U4 mm. in snout-vent

length.

Plethodon dorsalis angusticlavius Grobman

Plethodon cinereus angusticlavius Grobman (19hh: 302). Dundee (19h7:

117). Bragg and Hudson (1951: 89). Bragg (1955: 27-8).


pet- AM~N h0366, an adult male, collected at Mud Cave, near Fairy Cave,
Stone County, Missouri, by B. C. Marshall, on October 1, 1927.


Diagnosis:- A race of Plethodon dorsalis in which the width of the dor-

sal band is usually less than one-third of the width of the body.

Range:- Southwestern Missouri, northwestern Arkansas, and adjacent Okla-

homa, north of the Arkansas River (figure 12).

Description:- Living specimens of this form have not been examined. Of

33 preserved specimens (all from Arkansas), 10 are of the striped phase:

11 show no trace of a stripe, and the remainder show only a faint stripe

on the body, but at the base of the tail, it widens and becomes much

more well-defined. Typically striped angusticlavius also possess a

wider and brighter dorsal stripe at the base of the tail than on the

body. The brightness of the stripe in this region appears to be due to

a reduction in melanophore pigmentation in the dorsal stripe. The dorsal

stripe is often-irregular anteriorly, as in dorsalis.


The costal grooves usually number 18, the trunk vertebrae 19.

Vomerine teeth range from 1 to 8 in a series. The largest specimen






- 72 -


examined is 43 mm. in snout-vent length.



Plethodon cinereus


The red-backed salamander is the most abundant terrestrial

salamandor over most of its range, which includes much of eastern North

America. Two distinct color phases are present, one with a prominent

red or yellow dorsal stripe, the other uniformly dark in appearance.

The frequency of these color phases varies from one locality to another.

In some places, both phases occur in approximately equal numbers, in

others, one type may be rare or absent. The proportional distribution

of these color phases in the various populations has recently been

studied by Thurow, and it is hoped that the results of his work will be

published in the near future. Occasional specimens have been reported

that lack the dark pigment and appear entirely red. One specimen from

New Jersey lacked the red pigment in life and had a colorless dorsal

stripe.


Plethodon dorsalis has been considered a subspecies of P.

cinereus by some workers (Cope, 1889: 138; Blanchard, 1926: 269; Bishop,

1903: 236), and as a distinct species by others (Dunn, 1926: 158; Grob-

man, 1944: 308). Grobmn- points out that although the two forms are

largely allopatric, at some localities, especially in southern Indiana,

the two occur together, Grobman examined the series of dorsalis that

King (1939: 551) reported from the Great Smoky Mountains of Tennessee

and confirmed their identification. Specimens of both species found

together at the same localities are represented in the GSJNP collection.

These localities are White Oak Sinks (elevation 1750 feet) and the Sinks






- 73 -


on the Little River (elevation 1600 feet). On the Tennessee side of the

Great Smoky Mountains, P. cinereus is known from 1600 to 5000 feet and

P. dorsalis from 1200 to 2200 feet.


The two species also occur sympatrically in the Piedmont of

western Georgia. At two localities, 3.8 miles north of McDonough, Henry

County; and 8.5 miles north of Thomaston, Upson County, the two species

have been taken together. At all other localities in western Georgia,

where either P. c. polycentratus or P. d. dorsalis have been collected,

the other form has not been taken.


Bragg (1955:-27) reports that he collected a specimen of P. c.

serratus and a specimen of P. d. angusticlavis at the same locality in

Cherokee County, Oklahoma. Apparently the two species often occur to-

gether where their ranges overlap. Smith (19h8: 1) published several

new records of dorsalis from southeastern Illinois. P. cinereus and

P. dorsalis probably also occur synpatrically in that state. There

appears to be no evidence of intergradation at any of these localities,

confirming the conclusion of Dunn and Grobman that dorsalis and cinereus

have reached the species level of differentiation.


P. cinereus shows little apparent geographic variation over

most of its range, except in the frequency of occurrence of the two

color phases referred to earlier. Only in the Piedmont of Georgia and

in Arkansas and Oklahoma, where the populations of this species have

apparently become isolated from the parent stock, so we find differen-

tiation of the magnitude required for the recognition of subspecies.

The Arkansas and Oklahoma race serratuss) possesses a dorsal band with











serrations at each costal groove. This characteristic is sometimes

slightly developed in some specimens of other populations, but never

reaches the frequency of occurrence or degree of development present in

serratus.


The Georgia Piedmont subspecies (polycentratus) differs from

other populations of cinereus in its increased number of trunk verte-

brae. Data on the number of trunk vertebrae in samples of P. cinereus

are listed in table V. It also differs from most cinereus in possessing

red pignent on the belly between the front limbs. The cinereus popu-

lations in western North Carolina and eastern Tennessee are character-

ized by the complete absence of the dark lead-backed phase. P. c. poly-

centratus differs from these adjacent cinereus populations by the

presence of the lead-backed phase (38% of the type series of polycen-

tratus are dark phase).


Sanders and Smith (1949: 28) report a specimen of Plethodon

cinereus from Fern Lake, near Nacogdoches, Nacogdoches County, Texas.

This specimen (OS 556) lacks the serrate edges in the dorsal stripe

that are present in serratus, the nearest race geographically. It has

19 trunk vertebrae, but this number is not unusual in other populations

of cinereus. Mr. Sanders, who collected the specimen, informs me (in

letter of November 12, 1955) that it was taken with a dip net from a

bunch of fruiting sphagnum moss near the shore line, a most unusual

habitat for this terrestrial species. It may represent an accidental

introduction by man, and the record needs confirmation by the collection

of additional specimens from Texas before this state can be included in


- 74 -






- 75 -


the natural range of this species.



TABLE V

GEOGRAPHIC VARIATION IN THE NUMBER OF TRUNK VEKrEBRAE OF PL;THODON
CINEREUS


Number of trunk vertebrae
Locality
19 20 21 22 23


P. c. cinereus

New Brunswick, Canada 3 li 1

Nova Scotia, Canada 2 2 1

Quebec, Canada 1 1

Indiana 6 2

Missouri 1

New Jersey 7

Virginia (Blue Ridge Province) 7 33 3

Eastern Tennessee and western
North Carolina 5 40 9

P. c. serratus

Arkansas 3 19

P. c. polycentratus

Georgia 21 24 2






- 76 -


Plethodon cinereus cinereus (Green)
Salamandra cinerea Green (1818: 356).

Salamandra erythronota Green (1818: 356). (Type locality, probably

vicinity of Princeton, Now Jersey.)
Plethodon cinereus (Green). Tschudi (1838: 58). Dunn (1926: 163-80).

Sauropsis erythronotus (Green). Fitzinger (18L3: 33).

Plethodon erythronotus (Green). Baird (1850: 285).

Ambystoma erythronotum (Green). Gray (1850: 37).

Salanandra puncticulata Valenciennes in Dumeril and Bibron (1854: 87).
Salamandra agilis Sager (1856: L29). (Type locality, Detroit, Michigan)

Plethodon erythronotus cinereus (Green). Cope (1869: 99).

Plethodon cinereus cinereus (Green). Davis and Rice (1883: 26). Bishop

(1941: 196-219). Bishop (1943: 232-6). Grobman (1944: 300-2).
Plethodon cinercus erythronotus (Green). Cope (1889: 135).

Plethodon huldae Grobman (1949: 136). (Type locality, Hlawksbill Moun-

tain, Madison County, Virginia.)

Type:- Dunn (1926: 165) states that the type is not known to exist. The

type locality is probably in the vicinity of Princeton, New Jersey.

Diagnosis:- A Small Eastern Plethodon with a black and white mottled

belly; usually with 20 trunk vertebrae; and a straight-bordered dorsal

stripe in the red-backed phase.

Range:- Nova Scotia, New Brunswick, southern Quebec and Ontario, Canada;

south through the eastern United States to North Carolina, eastern Ten-

nessee and Kentucky, Ohio, Indiana, Illinois and southeastern iLissouri

(figure 13).






- 77 -


Figure 13. The distribution of the subspecies of Plethodon cinereus.





- 78 -


Description:- The dark, unstriped phase is usually characterized by the

absence of red lipophores, the presence of small white spots on the

dorsum (0.07-0.2 mm in diameter), and numerous ;~..allor brassy flecks on

the head, back, and tail. The belly is mottled with black and yellow

or white guanophores. The lateral guanophore pigment is sir.lar to that

on the belly.


The red-backed phase has sides and belly similar to the dark

phase. The white spots and brassy flecks on the dorsum! are reduced in

the area of the dorsal stripe, but are present on the head and tail.

The color of the lipophores in the dorsal stripe is variable, ranging

from red to yellow.


The costal grooves usually number 19, the trunk vertebrae 20.

Vomerine teeth range from 3 to 9 in a series. The largest specimen ex-

amined is 51 ram. in snout-vent length. Sexual maturity is reached at

about 35 mm. in snout-vent length.


Plethodon cinereus serratus Grobman

Flethodon cinereus serratus Grobman (194: 306-8). Bragg (1952: 23Jh).

Bragg (1955: 27-8).

Type:- CNHM 3946., a female, collected on Rich Mountain, Polk County,

Arkansas, at an elevation of 2500 feet, by Karl P. Schmidt and C. M.

Barber, on March 23, 1938.


Diagnosis:- A race of Plethodon cinereus in which the edges of the

dorsal stripe are serrated at each costal groove.






- 79 -


Range:- West-central uplands of Arkansas and adjacent Oklahoma, south of

the Arkansas idver (figure 13). Also reported by Bragg (1955: 27-8)

from Cherokee County, Oklahoma (north of the Arkansas River).


Description:- The dark phase is apparently rare in this form, only one

of 33 specimens examined lacked the red dorsal band. In red-backed in-

dividuals, the serrations on the edges of the dorsal stripe are present

on the body, but not on the tail. The serrations are due to the fact

that the red pigment in the dorsal stripe extends ventrolaterally toward

the top of each costal furrow. The usual absence of melanophores in this

extension of the dorsal stripe makes the saw-tooth edge of the stripe

conspicuous to the naked eye.


The costal grooves usually number 19, the trunk vertebrae 20.

Vomerine teeth range from 3 to 8 in a series. The largest specimen ex-

amined is 46 mrm. in snout-vent length.


Plethodon cinereus polycentratus Highton and Grobman

Flethodon cinereus polycentratus Highton and Grobman (in press).


Type:- UF 8376, an adult male, collected 2 miles northeast of Palmetto,

Fulton County, Georgia, by Albert H. Highton and Richard Highton, on

February 2, 1954.

Diagnosis:- A race of Plethodon cinereus in which the usual number of

trunk vertebrae is 21 or 22 (rarely 23).


Range:- The Piedmont of western Georgia (figure 13).


Description:- This race is similar in coloration to the typical sub-





- 80 -


species. It differs in possessing a greater number of body segments.

Vomerine teeth range from 3 to 7 in a series. The largest specimen is

112 m. in snout-vent length. Sexual maturity is reached at about 35

mm. in snout-vent length.


The Eastern Large Plethodons


This group, as defined by Grobman (194h: 266) on the basis of

larger size and fewer costal grooves than the other eastern plethodons,

includes six species that inhabit the eastern portion of the United

States. Plethodon glutinosus is the most widely distributed and all

the other species occur within its range. P. yonahlossee occurs in

the Southern Section of the Blue Ridge Province north of the French

Broad River. P. ouachitae, superficially very similar to yonahlossee,

lives in the Ouachita Al'oitains of Arkansas and Oklahoma. The re-

cently described P. caddoensis is known only fro- the Caddo Mountains

of Arkansas. P. jordani includes eight subspecies, all occurring in

the Southern Section of the Blue Ridge Province. The range of P.

wehrlei is centered in the Unglaciated Allegheny Plateau Section of the

of the Appalachian Plateaus Province. (See Grobman (1941) for an analy-

sis of the distribution of these forms.) Two recently described species,

P. dixi and P. Jacksoni are here considered races of wehrlei, because of

their close morphological similarity to wehrlei and the f.ct that they

replace wehrlei geographically.


There has been much speculation on the relationships of the

species within this section of the genus. Dunn (1926: 23) believes

this to be the most primitive group of the genus, with yonahlossee the






- 81 -


most primitive form. Dunn and Grobman (1944: 276) both believe the

relationship between yonahlossee and wehrlei is close. Hairston and

Pope (1948) suggest that yonahlossee is closely related to jordani and

that close similarity between some jordani and glutinosus is merely con-

vergence, but others think that the closest relative of jordani is glutin-

osus. Bishop (1941) even considered one race of jordani (shermani) to
be racially related to glutinosus. On the other hand, Grobman (19h4)

believed that jordani and closely related forms (now all considered

races of jordani) are different enough to warrant the erection of a
separate group, that he called the metcalfi group, distinct from all

the other Eastern Large Plethodons.

Characters studied by previous workers in attempting to de-

termine the morphological similarity and hence the relationships of

these forms, include size, number of vomerine teeth, number of costal

grooves, degree of sexual dimorphism, and pigmentation. In the present

study, most of these characters have been reexamined using large series

of specimens that, for the most part, were not available to previous

workers. Several characters have been found to be extremely variable

and not diagnostic of any one form. For example, Bishop (1941: 18),
Grobman (19t4: 287), and Hairston and Pope (1948: 274) all believed

that the Plethodon jordani group has fewer vomerine teeth than P.

glutinosus. I have counted the vomerine teeth of 269 Florida glutinosus

(figure lW), 125 Virginia glutinosus (the sIae specimens used by Pope

and Pope, 1949, in their study, and our counts essentially agree), 45

glutinosus from the Coastal Plain of Virginia and North Carolina (figure

15), 115 specimens of P. J. jordani (figure 16), 27 specimens of P. J.

shermani, 72 specimens of P. J. netcalfi, 53 specimens of P. J. mela-






- 82 -


ventris, 14 specimens of P. J. rabunensis, 29 specimens of P. J. teya-

halee, and h4 specimens of P. a. unicoi. For a given size, the range

of variation is quite similar for each form, although there is often a

statistically significant difference in the variability and/or the

ontogenetic rate of change in the different species. The data of Popo

and Pope (1951) indicate that P. ouachitae has a similar range of var-

iation in number of teeth as glutinosus and jordani, although the av-

erage number of teeth is slightly higher. The number of teeth in 60

P. wehrlei (figure 17) seems to be less than in the above forms, while

Pope (1950) shows that P. yonahlossee than the above forms. 39 P.

caddoensis, although small in size, have even more teeth than P.

yonahlossee of the sa'e size range (figure 18). Except between adult

wehrlei and yonahlossee, or wehrlei and caddoensis, there is consider

able overlap in the vomerine tooth counts of all the Eastern Large

Plethodons, and even in the case of these, only adults can actually be

distinguished on the basis of this character. It is true that large

series of adults of species that differ greatly in size (e.g. P. g.

glutinosus and P. J. metcalfi) will differ in average number of vo-

merine teeth, but this is mainly a reflection of the difference in size

between the two forms. This character obviously cannot be used as an

aid in identification, since specimens of the two species that are the

same size will have similar womerine tooth counts.


Several other supposed differences mentioned in the litera-

ture are not useful in determining relationships. All, except P.

wehrlei, have a similar number of costal grooves (see table VI). Sex-

ual dimorphism in size is present in several forms that have been

critically studied. The type of lateral guanophore pigmentation varies









- 83 -


S P glutinosus
24 (Pennsulo Florida)
22* *
2 a
2C ** ooooo o -

16 oloo A &, 6 o- d

12 o *


20 2 0 3 0 5 5 5 6


20 25 30 35 40 45 50 55 60
SNOUT-VENT LENGTH (mm)


Figure 1Ji.


Vomerine teeth of 269 peninsula Florida P. glutinosus


plotted against snout-vent length.


P. glutinosus
(Coostol Plain Vo B N.C)


. .
*


20 25 30 35 40 45 50 55 60 65 70
SNOUT-VENT LENGTH (mm)


Figure 15.


Vonerine teeth of 45 P. glutinosus from the Coastal Plain


of Virginia and North Carolina plotted against snout-vent


length.


65 70


"





a









- 86 -


P. jordonl


*
*.. .

.'. . . . .
*. -. .

*..
*
** ** { *-*
* -
~ ~ ~ w *
** *


20 25 30 35 40 45 50 55 60 65

SNO'JT- IhNT LENGTH (mm)








Figure 16. Vomerine teeth of 115 P. J. jordani plotted against snout-


vent length.


P wehrler


.. ..
C
* C


0C
C C **C
C l
C C C
C ** C
C **


20 25 30 35 40 45 50 55 60 65

SNOUT-VENT LENGTH (mm)


Figure 17.


Vomerine teeth of 60 P. w. wehrlei plotted against snout-


vent length.


4 - -

















P. coddoensil


0
@0
*0 0000
.H 0
0@ 4 0
0 04 0 0
0 0


0U i5 0U 35 40 45 50


55 60


SNOUT-VENT LENGTH (mm)




Figure 18. Vomerine teeth of 39 P. caddoensis plotted against snout-


vent length.


Southern Northern


ouochitoe
coddoensis / vc


Figure 19. Suggested phylogeny of the Eastern Large Plethodons.


glutinosus


V __ __ __


- 85 -





- 86 -


somewhat within a species (both individually and geographically), but

there appear to be no consistent differences between species.


There remain, then, only a few characters that can be used

to diagnose or distinguish the Eastern Large Plethodons. Each species

is sympatric with, and often coexists in the same habitat with one or

more of the other species without any evidence of interbreeding. As

far as we know, each is a genetically distinct unit, and there is much

evidence to indicate that different species have different ecological

requirements. Yet preserved specimens that have lost their pigmenta-

tion characters are often extremely difficult to identify because of

the morphological similarity of most of these salamanders.


P. wehrlei is distinguished on the basis of a greater amount

of webbing on the toes, by having an average of one more trunk verte-

bra, and by possessing fewer vomerine teeth than the other species.

P. yonalilossee may be recognized by its distinctive color pattern in

life. It also differs from the others (except caddoensis) in posses-

sing a greater number of vomerine teeth. P. ouachitae has a similar

color pattern to that of yonnhlossee, but it has fewer vomerine teeth.

I have found no character that will consistently separate glutinosus

and jordani. The chin of glutinosus is usually darker than that of

jordani, but certain populations of both species more closely resemble

the other (some Texas glutinosus have very light chins, whereas P. J.

teyahalee and some P. J. rabunensis possess dark chins). The close

morphological similarity between all the forms, except P. wehrlei,

indicate that they are a closely related group of species, with only

rehrlei separated from the others by a number of characteristics.





- 87 -


TABLE VI


THE NUMBER OF COSTAL GROOVES AND VERTEBRAE IN TII EASTERN LARGE

PIETHODONS


Fo No. of costal grooves No. of trunk vertebrae
Form15 16 176 17 18 19
15 16 17 16 17 18 19


P. w. wehrlei

P. w. dixi

P. yonahlossee

P. ouachitae

P. caddoensis

P. glutinosus2

P. J. jordani

P. j. metcalfi

P. j. shermani

P. j. unicoi

P. j. melaventris

P. J. rabunensis

P. 3. teyahalee


3 57


2 48


30 4


12 2

16

35 2


32 319 14


19 212 15


11 68

10 78


8 1


6 6h 3

h 56 1


5 67

1 39


2 24h


1
This is the only form in the table in which the same specimens were used
to count both costal grooves and trunk vertebrae. The data on both char-
acteristics are included only to show the close correspondence between
the two counts. No other specimen of any of the forms listed in the
table was included under both costal grooves and trunk vertebrae.
2
For a geographic breakdown of these counts, see table VIII.






- 88 -


The young of yonahlossee, some wehrlei, and two races of

jordani are known to possess dorsal red spots. These disappear in adult

wehrlei (except P. w. jacksoni) and Aordani, and become incorporated in-

to the dorsal red stripe of yonahlossee. Ho information is yet avail-

able on the very small young of ouachitae, caddoensis, and several of

the races of jordani, but young ouachitae may possess then (see Pope and

Pope, 1951: 1i5). The red dorsal spots appear to be definitely absent

in the young of glutinosus. Red pigment was absent in all of the newly

hatched young I have examined from Florida (Highton, in press), as well

as in very young specimens from many other localities. Dunn (1926: 139)

records a specimen of P. glutinosus from Clayton, Georgia, that had tiny

paired red dorsal spots, but this may well be a specimen of P. .. sher-

mani, known to occur within 10 miles of Clayton. Cope (1889: 141) also

records young specimens of glutinosus from caves in Montgomery County,

Virginia, possessing these spots, but the specimens were probably P. w.

jacksoni.


A reduction in the amount of melanophore pigmentation on the

chin occurs in yonahlossee, ouachitae, caddoensis, wehrlei, most races

of jordani (except teyahalee and some rabunensis) and in some Texas

plutinosus (albagula).


Most species possess a dark belly, but the four northern races

of jordani (jordani, shermani, unicoi, and especially metcalfi) are

light-bellied, as are some southern wehrlei.

P. yonahlossee and P. glutinosus (except for its southeastern

Coastal Plain representatives) attain a larger maximum size than the






- 89 -


other species. P. caddoensis appears to be the smallest Eastern Large

Plethodon. P. J. motcalfi might also be considered a dwarfed form.


Red pigment occurs in adult jacksoni, yonahlossee, ouachitae,

jordani, and shermani. Dorsal guanophores occur in glutinosus, alba-

gula, ouachitae, caddoensis, clensonae, and teyahalee. Lateral guano-

phores are usually present in all Large Eastern Plethodons, except for

four races of jordani (ordani, metcalfi, rielavcntris, and some shemani).


In summary, P. wehrlei seems to be the most distinct of the

Eastern Large Plethodons, while the others seem to be morphologically

very similar to each other, In ry opinion, the hypothetical ancestor

of the group might most reasonably be assumed to have been a moderate-

sized animal with a light chin and dark belly, probably with paired red

spots on the dorsum of the adult, possessing 17 trunk vertebrae, a short

vomerine series, and webbed toes. P. wehrlei is closest to this hypo-

thetical ancestor, although its body has become slightly elongated with

the addition of an extra trunk vertebra. The chin is still light in

all except glutinosus (albagula excepted) and one or two races of jor-

dani. The dark belly has remained in all but the four northern races

of jordani and in southern wehrlei. A larger size has been attained by

yonahlossee and glutinosus, while dwarfing has occurred in northern

jordani (especially metcalfi) and caddoensis. P. yonahlossee has a

much longer vomerine series than the others. The degree of relation-

ship indicated by a study of these characters would seem to indicate a

phylo.-eny as outlined in figure 19.





- 90 -


Plethodon wehrlei Group


Plethodon wehrlei

Plethodon wehrlei inhabits the unglaciated Appalachian Pla-

teaus Province in southwestern New York, western Pennsylvania, extreme

southeastern Ohio, West Virginia, and adjacent Virginia (whore it oc-

curs a short distance outside the Appalachian Plateaus Province).

This species is the most distinct of the Eastern Large Plethodons and

appears to occupy a somewhat isolated position in the group, differing

from the other species in several respects. There is usually more

webbing on the toes of this species, although occasional specimens of

other species, especially P. caddoensis and P. ouachitae, approach P.

wehrlei in this regard. P. wehrlei is the only Eastern Large Plethodon

that ncrmally has 18 trunk vertebrae; all the others usually possess 17.

P. wehrlei possesses fewer vomerine teeth than any other Eastern Large

Plethodon and it is the only species that has melanophore pigmentation

in the peritoneum.


Two close relatives of Plethodon wehrlei from southwestern

Virginia (P. dixi and P. jacksoni) have recently been described as dis-

tinct species by Pope and Fowler (19L9) and Newman (195h). P. dixi

appears to differ from P. wehrlei only in proportions and pigmentation.

It would seem best to regard it as a subspecies of P. wehrloi, since it

replaces the latter geographically. P. jacksoni, based on specimens

from an adjacent county, less than 15 miles from the dixi localities,

essentially differs from P. wehrlei in the retention of the juvenile

dorsal red spots in the adult. Young West Virginia wehrlei often possess

these spots, but they appear to be absent in more northern wehrlei.





- 91 -


Since jacksoni does not otherwise differ from some wehrlei and dixi,

it is also here regarded as a subspecies of P. wehrlei.


Several writers have commented on the geographic variation

in P. wehrlei. Netting (1936: 91) lists ways in which West Virginia

P. wehrlei differ from topotypic Pennsylvania specimens. The former

possess white spotting on the throat and chest, while in Pennsylvania

specimens the white spotting is absent. The lateral white pigment is

also more abundant in West Virginia material.


Dunn (1926: 135) mentions the presence of paired red spots on

the dorsum of a juvenile from Bristol, West Virginia. Brooks (190s:

231) reports that three adults, as well as most of the juveniles, in a

series of 22 specimens from Randolph County, West Virginia, also pos-

sess dorsal red pigment. Bishop (1941: 238) states that none of the

specimens of this species he has examined (presumably all from New York

and Pennsylvania) have shown the slightest trace of red pigment.


Grobman (1944: 287) has pointed out some of the above dif-

ferences between West Virginia and New York and Pennsylvania specimens,

and has also suggested that southern wehrlei may attain a greater size

than northern specimens. In view of these differences in northern and

southern P. w. wehrlei, this form should be further studied for other

evidences of geographic variation. It is possible that the northern

and southern populations should be recognized as distinct subspecies.

In the possession of reduced black pigmentation on the anterior portion

of the belly, southern wehrlei are more similar to dixi and jacksoni

than are northern wehrlei. In the presence of red spots on juveniles,

as well as in some adults, West Virginia specimens are similar to






- 92 -


jacksoni. The increased lateral white pigmentation in southern wehrlei

is also paralleled by jacksoni and dixi.


I have not carefully examined the pigmentation of any of the

races of wehrlei in life, although a casual examination of living speci-

mons from New York, West Virginia, and Virginia (dixi topotypes) was

made before the present study was contemplated. A comparison of the

geographic variation in pigmentation characters within the species, as

well as with other Plethodons is much to be desired. Pope and Fowler

(1949: 1) state that both "bronzy mottling" and ?small light flecks"

are present on the back of dixi. The former disappear rapidly in pre-

servative whereas the latter remain, although fading somewhat. Pope

and Fowler state that they have occasionally observed the "white fleck-

ing" in wehrlei, but never the "bronzy mottling." The white flecking is

probably the same type of spot evident on the specimen figured by Bishop

(194la: fig. 45). The red dorsal spots, present in young West Virginia

wehrlei, were not observed by Pope and Fowler in a large series of para-

typic dixi, including 59 juveniles. The belly of dixi is mottled (pre-

sumably with white guanophores on a melanophore background), whereas

the belly of wehrlei is usually uniformly pigmented with melanophores.

In size, dixi appears to be smaller than the other races. The speci-

mens of dixi that have been examined also appear to have proportionately

narrower heads and slenderer bodies than wehrlei.


Newman (1954: 12) states that the dorsum of jacksoni has "white

flocks" and "silvery mottling," the latter usually disappearing within

twenty-four hours after preservation. I.ottling on the belly is also

present, as in dixi. According to Newman, the dark belly pigmentation




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