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UFIR FMNH



Some Mexican land snails of the genera Coelostemma and Metastoma (Urocoptidae)
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 Material Information
Title: Some Mexican land snails of the genera Coelostemma and Metastoma (Urocoptidae)
Series Title: Bulletin of the Florida State Museum
Physical Description: 267-302 p. : illus. ; 23 cm.
Language: English
Creator: Thompson, Fred G ( Fred Gilbert ), 1934-
Publisher: University of Florida
Place of Publication: Gainesville
Publication Date: 1971
 Subjects
Subjects / Keywords: Coelostemma -- Classification   ( lcsh )
Metastoma -- Classification   ( lcsh )
Mollusks -- Classification   ( lcsh )
Mollusks -- Mexico   ( lcsh )
Genre: bibliography   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 302.
General Note: Cover title.
Statement of Responsibility: by Fred G. Thompson.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier: ltqf - AAA0811
notis - ABT1994
alephbibnum - 000305398
oclc - 04809607
lccn - 78321905
System ID: UF00001503:00001

Table of Contents
    Front Cover
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    Main
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    Back Cover
        Page 303
Full Text


UNIVERSITY OF FLORIDA
Gainesville
1970-1971



BULLETIN

OF THE


FLORIDA STATE MUSEUM


BIOLOGICAL SCIENCES


Volume 15


Number 5


SOME MEXICAN LAND SNAILS
OF THE GENERA COELOSTEMMA
AND METASTOMA (UROCOPTIDAE)

Fred G. Thompson


UNIVERSITY OF FLORIDA
Gainesville
1971









Numbers of the BULLETIN OF THE FLORIDA STATE MUSEUM are pub-
lished at irregular intervals. Volumes contain about 300 pages and are not
necessarily completed in any one calendar year.


OLIVER L. AUSTIN, JR., Editor
WALTER AUFFENBERG, Managing Editor
FRED G. THOMPSON, Assistant Editor


Consultant for this issue:

WILLIAM J. CLENCH

















Communications concerning purchase or exchange of the publication and all
manuscripts should be addressed to the Managing Editor of the Bulletin, Florida
State Museum, University of Florida, Gainesville, Florida 32601.


Price for this issue $ .50


Published 27 April 1971









SOME MEXICAN LAND SNAILS
OF THE GENERA COELOSTEMMA
AND METASTOMA (UROCOPTIDAE)



FRED G. THOMPSON1



SYNOPSIS: The following new taxa are described: C. leucosioma n. sp., C. bcenbix
n. sp., C. clipss n. sp., C. anaclasta n. sp., C. richardi n. sp., C. notogastor n. sp.,
C. iasraxis n. sp., C. farnax n. sp. and C. fornax ix n. ssp. Two new subgenera are
also proposed: Crycoryne n. subg. (type species: C. astraxis) and Styloptyx n. subg.
(type species: C. fornax). C. antricola Bartsch is reduced to subspecific status as
C. bourgeoisana antricola. C. iamplaxis Pilsbry, type species of the subgenus
Aperlaxis, is synonymized with C. coahuilCnsis (Bartsch). Metastoma is elevated
from a subgenus of Holospira to generic status and is closely related to Coclostemn-
ma. Aspects of the embryonic sculpture are determined for C. ,lizabelthae (Pils-
bry), C. b. bourgeoisana Bartsch, C. b. antricola Bartsch, C. iqualaensis (Bartsch),
C. hazelae Pilsbry, C. fusca (Martens), C. coahuilensis (Bartsch) and Mltastona
roemeri (Pfeiffer). These are features omitted in earlier descriptions of these
species.


INTRODUCTION

This is a preliminary report on some Mexican land snails of the
genus Coelostemma. Discussions of their anatomies will be presented
in a forthcoming paper on the phylogeny of the Mexican Urocoptidae.
The descriptions of some new species of Coclostenmma from southern
Mexico require a review of the status of Metastoma.
Coclostemma belongs to the Holospirinae, a subfamily confined to
Mexico, the southwestern United States, and a small area in Guatemala.
About 17 genera and subgenera are recognized throughout this region,
and undoubtedly additions will be made when the more poorly known


'Fred G. Thompsonr is Assistant Curator in Malacology at the Florida State
Museum. His research includes systematics, zoogeography, and ecology of land
and freshwater mollusks.


Thompson, Fred G. 1971. Some Mexican Land Snails of the Genera Coclostc'm-
ma and Metastoma (Urocoptidae). Bull. Florida State Mus., vol. 15, no. 5,
pp. 267-302.




5 .7 o.



268 BULLETIN FLORIDA STATE MUSEUM Vol. XV

parts of Mexico are further explored. The genera and subgenera are dif-
ficult to define, because their distinctions are based upon shell char-
acters, some of which may be polyphyletic in derivation. Coelostenuma
is recognized by its enlarged hollow axis. This character occurs in two
other genera, Metastoma and Allocoryphe, and close relationships may
exist between these groups.

ACKNOWLEDGEMENTS

During the course of this study I have been aided by several people who
have given me critical assistance. Angela Crane, British Museum (Natural
History), provided me with measurements and photographs of the type series of
Holospira fulsca Martens, which were necessary to restrict the name among two
species in the type series. Joseph Rosewater, U.S. National Museum (USNM),
loaned me the type series of Epirobia coahuilcnsis Bartsch so that aspects of its
embryonic sculpture could be determined. Gonzalo Halffter, Instituto Politecnico
Nacional, Mexico, sent me specimens of great interest and facilitated my field
work through the assistance and courtesies of his office. Field work in Mexico
was conducted with a collecting permit issued through the office of Rodolfo
Hernandez Corzo, Direccion General de La Fauna Silvestre, Mexico. To all of
these people I am grateful. Most of the material studied is deposited in the Flor-
ida State Museum collections, University of Florida (UF).


Genus Coclostenmma Dall

Coclostemma Dall, 1895; Nautilus, 9: 50.- Pilsbry, 1900; Man. Conch., II, 15:
98-99.- Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 58.- Pilsbry, 1953; Proc.
Acad. Nat. Sci. Phila., 105: 156. (Type species by original designation: Hlolo-
spira clizabcthac Pilsbry, 1889).
Megaxis Pilsbry, 1946; Land Moll. N. Amer., 11(1): 123. (Type species by orig-
inal designation: llolospirafusca Martens, 1897).

The shell is dextral, cylindroid in shape, bears a large hollow axis
and lacks any lamella within the aperture. Lamellae or other sculpture
may be present on the axis.
Coelostemma consists of four subgenera. The typical and most wide-
ly distributed subgenus has minute granular sculpture on the first two
embryonic whorls followed by fine vertical ribs on the last half embry-
onic whorl. The second subgenus, Apertaxis, has only fine granular
sculpture on the embryonic whorls. The two remaining subgenera have
smooth embryonic whorls. They are localized in the same general re-
gion in north central Mexico and probably have a common origin from
a single Coelostemma ancestry.
Coclostemma is most closely related to Metastoma. The large hol-
low axis occurring in both genera contrasts strongly with the narrower,







THOMPSON: MEXICAN LAND SNAILS


barely perforate axis of most other Holospirinae. This expanded axial
condition is approached in some species of the Holospira subgenus Al-
locoryphe, but whether a close relationship exists between Coclostemma
and Allocoryphc is uncertain. The phylogenetic relationships within
Holospira s. I. and Coelostcmma are poorly established, and only ex-
tensive field work in Mexico will clarify the relationships.

Subgenus Coelosetmma Dall

The typical subgenus has about two embryonic whorls that are sculp-
tured with minute granules, which on the last 4 embryonic whorl are
replaced by fine vertical threads or riblets. The axis is either smooth or
has fine vertical threads and may bear a spiral swelling just above the
floor of the whorls.
The center of evolution of Coelostemma (s. s.) is in southern Mex-
ico, primarily in Guerrero, Oaxaca, and Morelos. It probably will be
found extensively in Puebla and Michoacan with some species occur-
ring in adjacent regions of Veracruz and Colima. My field experiences
indicate the subgenus probably does not extend south of central Oaxaca.
Some species from northern Mexico are also referred to Coclostem-
ma (s.s.). Two species, C. marrsi Drake, 1951 and C. reitcri Drake,
1951, are known only from broken shells denuded of embryonic whorls,
and their subgeneric allocation cannot be determined by embryonic
sculpture. The axis of C. greggi Drake, 1951 is very narrow, and the
species herein is placed in lHaplocion Pilsbry, 1902. These three species
are from Chihuahua. C. freytagi Bartsch, 1950, also from Chihuahua,
C. dalli Pilsbry, 1902 and C. saltillensis Pilsbry, 1953 from Coahuila
and C. lissocentrum Pilsbry, 1953 from Nuevo Le6n are described as
being typical for Coelostcmma (s.s.). Details of the embryonic sculpture
for the last three species need to be confirmed.
Coclostemma (s. s.) consists of five or more groups of species, four
of which are readily defined while others are less clearly delimited be-
cause of limited material from southern Mexico. The typical group,
consisting of C. elizabethae and some other species from Guerrero and
Oaxaca, has fine, oblique riblets on the axis and an opaque, livid-white
shell of moderate or large size. A second group, consisting of C. hazclac
and two new species, has a smooth axis but is similar in other respects
to the typical section. A third group, consisting of C. borrgcoiisana
and its allies, has the fine, oblique ribs on the axis broken into serrations
and granules. Another group of small brownish species from Oaxaca
(C. richardi and C. notogastor) has oblique riblets on the axis such as
occurs in C. clizabethae, but the snails' small size and their color pre-


1971







BULLETIN FLORIDA STATE MUSEUM


sent an appearance that is quite different from other species groups.
Two other species, both of which have smooth axes, are similar in ap-
pearance to this group and probably are derived from it.

Coelostemma ('lizabethac (Pilsbry)

Holospira clizabethae Pilsbry, 1889; Proc. Acad. Nat. Sci. Phila.: 81; pl. 3, figs.
1-5.- Crosse, 1892; Jour. de Conchyliologie: 272; pl. 5, figs. 6-6a.- Martens,
1897; Biol. Cent. Amer.: 635.- Pilsbry, 1903; Man. Conch., II, 15: 99-100; pl.
15, figs. 6-15; pl. 27, fig. 27. (Type locality: Amula, Guerrero).
Holospira (Coclostemma) elizabethae Pilsbry, Dall, 1895; Naut., 9: 50.- Dall,
1895; Proc. U. S. Nat. Mus., 19: 347.- Bartsch, 1906; Proc. U. S. Nat. Mus., 31:
149.
Coclostenmma clizabethae (Pilsbry), Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 58.
Holospira claviformis von Martens, 1897; Biol. Cent. Amer.: 277; pl. 16, figs.
10-16. (Type locality: Amula, Guerrero).

This species was collected from three places near the type locality.
The samples show no variation not encompassed in earlier descriptions
by Pilsbry (1889, 1902). The embryonic whorls are low and are sep-
arated by a relatively weakly-impressed suture. The first two or so em-
bryonic whorls are sculptured with fine granules. The following quarter
whorl bears fine axial ribs that begin along the upper suture, become
increasingly intense, and grade into the coarser sculpture of the follow-
ing post-embryonic whorl (Fig. 1, A).

SPECIMENS EXAMINED.--GUERRERO:- 11.2 mi. E of Tixtla, 6500 ft. elev.
(UF 20819); 7.7 mi. WSW of Chilapa, 6400 ft. elev. (UF 20820); 2.3 mi. WSW of
Chilapa, 5300 ft. elev. (UF 20818).

Coelostemnma iqualaensis (Bartsch)

Holohpira (Coelostemma) iqualacnsis Bartsch, 1926; Proc. U. S. Nat. Mus., 70:
3-4; pl. 1, fig. 12. (Type locality: Iquala [Iguala], Guerrero).
Coelostemma iqualaensis (Bartsch), Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 58.

The material listed herein was collected from two localities that lie
about 25 miles apart. Both samples demonstrate considerable intra
population variation in shell dimensions (Table 1).

The specimen illustrated (Fig. 1, F) has stronger vertical riblets on
the embryonic whorls than is usual. The sculpturing is normal in all
other aspects.

SPECIMENS EXAMINED.-GUERRERO:- 7.7 mi. N of Tonalapa, 3400 ft.
elev. (UF 20998); 5.5 mi. SW of Buenavista de Cu6llar, 4100 ft. elev. (UF
20999).


Vol. XV







THOMPSON: MEXICAN LAND SNAILS


TABLE 1. MEASUREMENTS (in mm) OF Two POPULATION SAMPLES OF C. iqualaenis.

Number Length Width Aper. H. Aper. W. Whorls

20998 (24) 19.1-29.0 6.8-7.9 4.3-4.8 4.2-4.5 16.8-21.9
20999 (40) 18.9-25.2 5.8-7.7 4.0-4.5 4.0-4.8 15.7-19.1


D


1ij,
E


FIGURE 1. Apical sculpture of Coelostcmma. A. C. clizabe'thae (Pilsbry) (UF
20891). B. C. eclipes new species holotypee). C. C. fusca (Martens) (UF 20916).
D. C. anaclasta new species holotypee). E. C. bembix new species (paratype). F.
C. iquialansis (Bartsch) (UF 20999). G. C. notogastor new species (paratype). H.
C. richardi new species (paratype). I. C. Icucostoma new species holotypee).

Coelostemma bourgeoisana bourgeoisana Bartsch

Coelostemma bourgeoisana Bartsch, 1942; Jour. Wash. Acad. Sci., 32: 187; fig. 1.-
1943; ibid, 33: 58. (Type locality: Ixtapan de la Sal, Mexico).

This snail is common on limestone terrain about the type locality
and is a local variation of the more widely distributed antricola, with
which all parameters of the shell intergrade (Table 2). Aspects of the
embryonic sculpture of both subspecies are similar to those of C. iqua-
laensis and other species from southern Mexico.


F







BULLETIN FLORIDA STATE MUSEUM


TABLE 2. MEASUREMENTS (in mm) OF FOUR POPULATION SAMPLES OF
C. bourgeoisana.

Subspecies No. Length Width Aper. H. Aper. W. Whorls

bourgeoisana 21147 (136) 12.6-20.0 4.3-5.6 2.8-3.6 3.1-3.7 13.4-17.5
antricola 21150 (50) 14.1-25.1 4.8-5.6 3.0-4.2 3.2-3.9 16.0-21.8
antricola 21149 (45) 17.0-24.9 4.8-5.5 2.9-3.8 3.0-3.7 17.2-21.4
anltricola 21151 (40) 18.8-25.9 4.9-5.9 3.1-3.8 3.0-4.0 17.5-22.7


SPECIMENS EXAMINED.-MEXICO:- 0.5 mi. N of Ixtapan de la Sal, 6200
ft. elev. (UF 21148. 146); 0.5 mi. SW of Ixtapan de la Sal, 6500 ft. elev. (UF
21147. 136).

Coelostemma bourgeoisana antricola Bartsch

Coelostemma antricola Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 58; fig. 5.
(Type locality: ravine near Las Grutas, Cacahuamilpa, Guerrero).

This subspecies previously was known only from two specimens
collected at the type locality.

SPECIMENS EXAMINED.-MEXICO:- 14.3 mi. SE of Tonatico, 4900 ft. elev.
(UF 21149.45). GUERRERO:- 7.8 mi. NE of Taxco, 5800 ft. elev. (UF 21150.
50); 16.8 mi. NE of Taxco, 4200 ft. elev. (UF 21151. 40).

Coelostemma leucostoma new species

DIAGNOSIS.-A medium-sized cylindrical, ribbed species related to
C. bourgeoisana because of the similar sculpturing on the axis in the
two species. C. leucostoma differs from C. b. bourgcoisana and C. b.
antricola by its slender shape, more attenuate apex, and less strongly-
arched whorls.

SHELL (Fig. 2, A-E).-The shell is medium-sized (about 14-20 mm
long), cylindrical, slender, and narrowly rimate or imperforate. The
shell is dull, light tan and the inside of the aperture is white. The apex
is attenuate, consisting of about 9-10 nearly flat-sided whorls. The fol-
lowing whorls are nearly uniform in diameter, decreasing slightly near
the base. The aperture extends forward and laterally on a moderately-
long neck. The neck is rounded on the base and slightly flattened over
the parietal wall. Whorls 15.8-20.1 (19.8 in holotype). The suture on
the apex and the cylinder is distinctly impressed though the whorls are


Vol. XV








IIlOMPSON MEXICAN LAND SNAIllS


Fimvnr 2 (',o'fstr:uina ieli ltonl new spe)In A Holotype B-E. Paratypes.







BULLETIN FLORIDA STATE MUSEUM


weakly arched. The embryonic shell consists of 2.2-2.5 whorls that are
rounded and button-like, the second decidedly larger than the first. The
first two embryonic whorls are sculptured with numerous fine granules,
which are replaced on the last i embryonic whorl by fine regular ribs
that become increasingly strong and grade into the coarser sculpture on
the following apical whorls (Fig. 1, I). The apical ribs are almost uni-
formly spaced and widest at the base, where they form white knobs.
The ribs on the subsequent whorls are weakly arched, about as wide as
their interspaces and lack basal knobs. There are about 35-47 ribs on
the penultimate whorl (38 in holotype). The ribs become stronger and
more widely spaced on the neck of the last whorl and extend around the
base and into the umbilicus where they are finer and sharper. The aper-
ture is nearly ovate in shape, being slightly flattened dorsally. The
peristome is moderately expanded around the aperture, being widest
along the base and narrowest dorsally. The axis is about M the diameter
of the shell, is spindle-shaped within each whorl, and bears fine, oblique
axial ribs that are weakly serrate.
Length of shell 14.2-20.5 mm (19.6); width 4.0-4.6 mm (4.4); aper-
ture height 2.7-3.0 mm (3.0); aperture width 2.9-3.4 mm (3.2). Meas-
urements in parenthesis pertain to the holotype.
TYPE LOCALITY.-Ruinas de Xochicalco, Morelos; 4900 ft. elev.
HOLOTYPE: UF 21145, collected 11 June, 1966 by Fred G. Thomp-
son. PARATYPES: UF 21146 (113); Dept. Zoologia, Instituto Politec-
nico Nacional, Mexico (25); same data as the holotype. Snails were col-
lected near the ruins from under limestone blocks over a caliche. The
area contained submesic scrub and trees that were closely browsed by
sheep.
REMARKS.-This species is closely related to C. bourgeoisana. It
differs from the latter by its more attenuate apex, nodular ribs on the
apex, and its flatter whorls. Aspects of the apical sculpture also sug-
gest a relationship with C. richardi, described below. The two species
are readily distinguished by their shapes and their axial sculpture.
ETYMOLOGY.-The specific epithet is derived from the Greek
leukos, meaning white, and stoma meaning mouth and refers to the
white aperture in this species.

Coelostemma hazelae Pilsbry

Coelostemma hazelae Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105-159; pi. 5,
fig. 4. (Type locality: between Chilpancingo and Mazatlan, Guerrero).

This species, previously known only from the holotype, is repre-


Vol. XV






1971 THOMPSON: MEXICAN LAND SNAILS 275

sented by two series from near the type locality. Specimens from 2.2 mi.
NNE of Mazatlan, Gucrrcro, 4800 ft. alt. (UF 20996) are similar to
the holotype in most respects, though most individuals are slightly
more slender (Fig. 3, A-C). Specimens from 3.4 mi. NNE of Mazatlan,
Gucnero, 4700 ft. alt. (UF 20997) differ by being considerably shorter
stockier, though of similar width to the holotype (Fig. 3, D-F).
As in other species of Coelostemma from southern Mexico the er-


A B


D E


FIcunr 3. CroI,.rtmma hlazlae Pilsbry A-C 2.2 mi. NE Mazatlan, Guerrero.
D-F. 3.4 mi. NNE Mazatlni, Guerrero.






BULLETIN FLORIDA STATE MUSEUM


bryonic whorls are sculptured with minute granules on about the first
two whorls. The following half whorl or so bears weak axial thread-rib-
lets that grade into coarser riblets on the following postembryonic whorl.

Coelostemma eclipes new species

DIAcNosis.-A species distinguished by its moderately-large size
(usually about 18-20 mm long), opaque, whitish color, subelliptical
shape, costulate lower whorls, imperforate axis, moderate neck, and
smooth axis. Beacuse of its smooth axis it is related to C. hazelae and C.
bembix, both of which occur in adjacent areas of Guerrero. C cclipes
differs from C. hazelae by its larger size, larger caliber whorls, costulate
lower whorls, imperforate axis and longer neck behind the aperture.
The neck also bears a basal impression that is absent in C. hazelac. C.
cclipe's is distinguished from C. bembix by the numerous peculiarities
of the latter species described below.
SHELL (Fig. 4, A-E).-The shell is moderately large and stocky and
is subcylindrical or elongate-elliptical in shape. The widest portion lies
just below the apical cone. The apex consists of about 7-8 whorls, is
elevated, and is slightly convex in outline with protruding embryonic
whorls. The shell is dull-white over most of the spire, with a dark gray
apex. The umbilicus is imperforate. Whorls, 12.7-16.4 (16.4 in holo-
type). The whorls are moderately-arched on the apex but are nearly
flat on the spire. The 2.5-3.1 embryonic whorls (3.0 in holotype) are
offset by a deeply-impressed suture (Fig. 1, B). The first two embryonic
whorls are sculptured with dense, minute granulations. The subse-
quent embryonic whorl bears strong, oblique riblets that are of the
same intensity as those on the following postembryonic whorl. The first
three postembryonic whorls bear oblique riblets that are about half the
width of their intervals. The remainder of the apex and most of the
spire are nearly smooth, with only irregular incremental striations. The
last 2-3 whorls bear heavy, rounded ribs that are strongest on the last
whorl. The aperture is extended forward from the body whorl for
about 2 mm. The neck is flattened dorsally and bears on its base a
moderate, linear impression that forms a low callused ridge internally.
The aperture is usually wider than high and is ovate-auriculate in shape.
The parietal wall bears a weak fold similar to that in C. bcmbix. The
peristome is moderately expanded, being narrowest at the posterior
corner and widest along the baso-columellar margin. The axis is smooth
and about 3-4j the diameter of the shell. It is spindle-shaped within
each whorl and bears a low, spiral swelling just above the floor of the
whorls.


Vol. XV







1971 IHOIP'SON MEXICAN LAND SNAIL.S 277

Length of shell 14,4-20.2 inmi (200), width 5.9 6.9 mm (6.4), aper-
ti'o height 3.3-4 1 mm 0); apl'tl-re width 3 542 mm (4 2) MI as
i ni 'nlnts in pi)al etli'sis pcilin to hllot )pe
TI'F ].oc LIIY.-A ln(imstone ledgc 16.4 mi. N of Ziunpanigo del


a F


FI,' ili 4 ('(jrih ln ill),, c/lch s w S}-'p l A I [olofpei B E laityvpes






BULLETIN FLORIDA STATE MUSEUM


Rio, Guerrero; 2300 ft. elev. Snails were found on the ledge along clay
seams aestivating beneath the fronds of a small fern. HOLOTYPE: UF
21210, collected 12 June, 1966 by Fred G. Thompson. PARATYPES:
UF 21211 (55); Instituto Politecnico Nacional, Mexico (5); same data
as the holotype.
REMARKS.-C. eclipes is a member of a small group that also in-
cludes C. bembix and C. hazelae. These species have in common a mod-
erately-large, opaque-white shell and a smooth axis. C. lissoccntrum
Pilsbry from Nuevo Le6n is similar in these characteristics, but no
close relationship to the other three species is apparent. Similarly C.
fusca (Martens) and C. anaclasta have smooth axes, but both species
are more similar in other shell aspects to the other species within the
genus than to the hazelae group.
ETYMOLOGY.-The species name eclipes is taken from the Greek
eklipcs, meaning devoid of or wanting, and refers to the snails smooth
axis, lacking ribs or other sculpture.

Coelostemma bembix new species

DIAGNOSIS.-A species characterized by its globose, pupiform
shape with an abbreviated spire consisting of scalariform whorls. In
addition the auriculate-shaped aperture is extended forward on a long
and recurved neck. The parietal wall of the aperture bears a large,
laterally-compressed tubercular fold. Other characteristics include a
wide, smooth axis, an imperforate umbilicus and the presence of oblique
ribs on the apical cone and the last one or two whorls, while the inter-
mittent whorls are feebly striate.
SHELL (Fig. 5, A-F).-Medium-sized and stocky. The shape is high-
ly variable, ranging from depressed pupiform to globular. The apical
whorls are conspicuously suppressed, with the embryonic whorls pro-
truding as a short spike. The lower whorls decrease in size and the
aperture is born on a long recurved neck. Whorls 13.0-15.0 (14.2 in
holotype). Embryonic whorls 2.0-3.0 (2.8 in holotype). The first two
embryonic whorls are minutely granular (Fig. 1, E). The last half of
the second embryonic whorl bears increasingly distinct vertical ribs
that are about one-third the width of their intervals. The following 4-6
apical whorls are strongly ribbed with widely-spaced, slightly oblique
axial ribs. The first four post-embryonic whorls are strongly arched on
the summit. The next 2-3 whorls, which form the widest part of the
cone, are progressively flattened and scalariform. Below the periphery
of the cone the shell usually is truncate and has 3-5 smooth, weakly-


Vol. XV






1971 IIO [IPSON MENXICAN LAND SNAllS 279

l (Whld Xhoi iI the middle Thie o I (t two whorls "l e iossd I1
str(mnig idl -spIac the neck of tihe last whoI lhe lit t W ho I lw. is abont 21-30 ribs (22 i
holot' p'). The aipeirltri extends fori an d onl long e'cur\ ed neck that is
rounded X(.'pt ol 1 weaIk allrl( at the pi ital-c ioluiiiilla miai gin
T110 umbll cus is inperforate Tli' apcltitm is Uiiigulanly o Late 01 p\ ri


A B


D E


Firl- r 5 ( oilio rn1 hil n !iri i\ 1n slulx e A Holotx Hl -l' araitpes







BULLETIN FLORIDA STATE MUSEUM


form and is usually higher than wide. Internally the parietal wall bears
a large, medium, laterally-compressed tubercular fold. The peristome
is narrowly reflected around the aperture with the base extended and
trumpet-shaped. The axis is about one-third the diameter of the shell
near the middle and tapers to a very narrow tube in the last three
whorls. The axis is smooth, is slightly spindle-shaped within each
whorl, and bears a weak spiral swelling just below the middle.
Length of shell 15.3-18.9 mm (16.7), width 7.0-8.6 mm (8.0); aper-
ture height 3.4-4.4 mm (4.3), aperture width 3.6-4.6 mm (4.1). Meas-
urements in parenthesis pertain to holotype.
TYPE LOCALITY.-Guerrero, 12.6 mi. N of Zumpango del Rio,
2300 ft. elev. At this point the Federal Highway 95 crosses a tributary
of the Rio Balsas. Snails were collected on a limestone ledge above an
old road cut paralleling the east bank of the river. They were found be-
neath the fronds of a small fern growing along crevises in the ledge.
IIOLOTYPE: UF 20901, collected 13 June, 1966 by Fred G. Thomp-
son. PARATYPES: UF 20900 (110); Dept. Zoologia, Instituto Politec-
nico Nacional, Mexico (10); same data as the type.
REMARKS.-C. bnembix is similar in shape to C. cadria Bartsch
among the known species, although its relationship to C. adria is not
close. The most noticeable peculiarities of C. bcmbix include the scalari-
form apical whorls, the reflexed neck of the last whorl and the tuber-
cular fold in the aperture. Additional differences that distinguish C.
hcnbbix from C. adria include the sculpture on the middle portion of
the shell, the lack of sculpture on the axis, and the imperforate umbili-
cus. C. adria has weak riblets on the middle whorls, a modification of
the stronger sculpture below and above, its axis has feeble vertical
threads, and the umbilicus is narrowly perforate.
ETYMOLOGY.-The specific name is taken from the Greek bcmbix,
a top, in reference to the appearance of this snail.

Coelostemma anaclasta new species

DIAGNOSIS.-A moderately small species characterized by its cla-
vate shape with protruding embryonic whorls, its peristome located on
a long, reflexed neck that is weakly concave along its basal side, its
narrowly rimate or imperforate umbilicus, and its smooth axis that is
spindle-shaped within each whorl. The sculpture on the embryonic
whorls is minutely granular. The following apical whorls bear heavy,
oblique axial ribs that tend to be crenulate along their lower suture
and are very much reduced in intensity or are obsolete on the lower
wlhorls.


Vol. XV







1971 I'HOIPSON MEXICAN LAN ) S\\1,S 281

Smo, (Fig 6. A-F) -TI shell is mode atch sna]] (about 12-15
mm lon)) and clavate II sThap'. ITh ape riliie extends liibwa.d on a
long reflexed neck. he iumnlilis is nairoi\ly i nmate or ulperoiate.
The coili is dull tan, ancd ti shell is subtanslieent Ih loie nolo) nioc
whoils protirde strongly to flrm a nipple-like ape\. The next 6-7
wIhorls rapidly inmi .ese in 1si to loirm 1 conical apex that is con\x\
in outl ne The remaining 6-7 whorls gradually decrease in si/ The
last whoml nds in a long, reflexed neck about 1.4 2.2 mm long The


D E F
Ficum 6. ('il. Co.lme anacaila A sp, i.ee'E A, D Hololype B lC. Puatype.
E 11,1 nl, S Colima, (1Clima F7 2 ml. ESE Colhia, Cohlmi







BULLETIN FLORIDA STATE MUSEUM


base of the last whorl is flat and bluntly angular at the periphery. The
nearly quadrangular neck has a broad, shallow impression on the base
and a slightly-flattened dorsal surface. There are 15.1-16.7 whorls, in-
cluding 2.5-3.1 embryonic whorls. The embryonic whorls (Fig. 1, D)
protrude strongly, have a deeply impressed suture and are sculptured
with very fine granules. The last quarter embryonic whorl bears fine,
indistinct, oblique threads that phase into the axial ribs on the succeed-
ing whorl. The apical whorls are nearly flat, tend to be scalariform
near the periphery, and bear strong, oblique ribs that are weakly crenu-
late along the lower suture. The post-apical whorls are nearly flat,
but have a distinctly impressed suture and are sculptured with barely
distinguishable axial riblets that may be obsolete on some whorls. The
last whorl bears about 30 oblique arched ribs that are strongest near
the base of the neck and become sharp and irregular on the neck. The
aperture is ovate, has a conspicuously reflected peristome, and is about
0.2 mm broader than wide. The peristome is broadest along the basal
margin and narrowest along the posterior angle. Internally the throat is
subtriangular in cross-section, resulting from a weak invagination on
the base of the neck and a weaker impression on the dorsal surface. The
axis is broadest in the apex and decreased in size through the last whorl,
although there is no appreciable change in the caliber of the lower
whorls. The axis is spindle-shaped within each whorl, is smooth and
marked with irregular, opaque white streaks.
Length of shell 13.0-15.5 mm (15.5), width of shell 4.7-5.1 mm
(5.1), aperture height 2.3-2.8 mm (2.8), aperture width 2.5-2.8 mm
(2.8). Measurements are based on the type series. Those in parenthesis
pertain to the holotype.
GEOGRAPHIC VARIATION.-The type series is characterized by hav-
ing a raised apex that is conspicuously concave in outline below the
embryonic whorls, by having weakly distinguishable, if irregular, ribs
on the lower whorls, and by having a relatively long neck on the last
whorl (Fig. 6, D). Specimens of a series from 11.1 mi. S of Colima
have a raised conical apex that is weakly convex below the embryonic
whorls, the whorls below the apex are sculptured only with incremental
striations, and the neck tends to be shorter (Fig. 6, E). Shells from 7.2
mi. ESE of Colima are similar to the last series in sculpture, but have an
even shorter neck and have a suppressed spire (Fig. 6, F).
TYPE LOCALITY.-Colima, 1.9 mi. NE of Tecolapa, 700 ft. elev.
(Tecolapa is a small town located on the Colima-Manzanillo Highway
and is about 25 mi. SSW of Colima). Snails were found aestivating in
cracks in a small limestone ledge at the head of a small ravine about
300 yards west of the highway. The vegetatation consisted of a dense


Vol. XV






THOMPSON: MEXICAN LAND SNAILS


xeric scrub forest. HOLOTYPE: UF 20927, collected 1 June, 1966 by
Fred G. Thompson. PARATYPES: UF 20928 (20); Dept. Zoologia,
Institute Politecnico Nacional, Mexico (4); same data as the holotype.

OTHER LOCALITIES.-COLIMA:- 11.1 mi. S of Colima, 1400 ft. elev. (UF
20926); 7.2 mi. ESE of Colima, 1200 ft. elev. (UF 20925).

REMARKS.-C. anaclasta is readily distinguished from all other
species by its general external appearance and its smooth spindle-
shaped axis. Of the other known species with a smooth axis it resembles
C. fusca most closely. It differs from C. fisca by its claviform shape, its
long, reflexed neck, and its costulate sculpture on the apical whorls.
C. anaclasta is remarkably like C. bembix in its long, reflexed neck
and its smooth axis, but the similarities between the two species are
secondary and do not indicate phylogenetic relationships. These char-
acters also occur in Metastoma roemeri (Pfeiffer), a species that is con-
sidered only remotely related.
ETYMOLOGY.-The specific epithet is taken from the Greek ana-
klastos, meaning bent back or reflected, and refers to the flexed neck
of the aperture in this species.

Coelostcmma fusca (Martens)

lHolospira fusca Martens, 1897; Biol. Cent. Amer.: 281; pl. 16, figs. 20-24 (not 19).
(Type locality: Omilteme, Guerrero).
Holospira (Haplocion)fusca Martens, Pilsbry, 1902; Man. Conch., Ser. II, 15: 95-96,
pl. 25, figs. 8-10, 12-14.- Bartsch, 1906; Proc. U. S. Nat. Mus., 31: 146.
Ilaplocion fusca (Martens), Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 56.
Ilolospira (Alegaxis) fusca Martens, Pilsbry, 1946; Monogr. Acad. Nat. Sci. Phila.,
(3), II: 123.
Coelostenima fusca (Martens), Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105:
156.

The species is commonly distributed from 6500-8000 feet elevation
in the mountains to the east and west of Chilpancingo, Guerrero. Within
this area it is found in mesic oak and mixed oak-conifer forests, where
it is found characteristically on limestone. It undergoes considerable
local variation in size: The variation is not correlated with elevation
but is characteristic of particular colonies. All other aspects of the shell,
including sculpture, show little variability between populations.
Measurements of three population samples are given in Table 3.
The series from 0.6 mi. ESE of Omilteme (UF 20916) is considered
topotypic and encompasses most of the measurements given by Martens
(1897: 281). Measurements that he gives for his largest specimens






BULLETIN FLORIDA STATE MUSEUM


and his first figure (P1. 16, Fig. 19) represent a species of Ilolospira
(s.s.) presently undescribed.

TABLE 3. MEASUREMENTS (in mm) OF THREE POPULATION SAMPLES OF C.fusca.

Number Length Width Aper. H. Aper. W. Whorls

20911 (45) 11.8-16.3 3.6-4.2 2.0-2.4 1.9-2.3 15.7-20.0
20916 (40) 9.3-14.6 3.1-3.7 1.7-2.3 1.7-2.1 14.2-20.1
20913 (58) 10.4-12.4 3.0-3.7 1.8-2.0 1.8-2.0 13.7-18.5


The sculpturing of the first four whorls is illustrated (Fig. 1, C).
The embryonic whorls bear dense minute granulations, which are re-
placed on the following whorls by irregular, fine, oblique striations.
TYPE LocALITY.-Omilteme, Guerrero. LECTOTYPE by present
designation: British Museum (Natural History) 1901.6.22.1051, col-
lected by H. H. Smith. The British Museum has eight syntypes of this
species. Four specimens of Ilolospira sp. are also included in the type
series (Mrs. Angela Crane, pers. comm.).

OTHER LOCALITIES.-GUERRERO:- 11.2 mi. E of Tixtla, 6500 ft. elev.
(UF 20911); 9.8 mi. SW of Chilpancingo, 7100 ft. elev. (UF 20917); 11.4 mi. W
of Chilpancingo, 8400 ft. elev. (UF 20912); 12.4 mi. SW of Chilpancingo, 8400 ft.
elev. (UF 20918); 6.2 mi. ESE of Omilteme, 6800 ft. elev. (UF 20913); 5.5 mi.
ESE of Omilteme, 7000 ft. elev. (UF 20914); 3.5 mi. ESE of Omilteme, 7200 ft.
elev. (UF 20915); 0.6 mi. ESE of Omilteme, 7900 ft. elev. (UF 20916).


Coelostemma richardi new species

DIAGNOSIS.-A small claviform species (about 11-15 mm long) with
a moderately-wide umbilicus, strong, close costulate sculpture through-
out the length of the shell, 3-4 upper whorls that are weakly scalariform
and on which the ribs form nodular crenulations along the outer edge,
and a hollow axis that is spindleform within each whorl and bears irre-
gular, oblique thread-riblets.
SHELL (Fig. 7, A-E).-The shell is small and claviform. The umbil-
ical opening is moderately large and elliptical in shape. The color of the
spire is grayish-white. The embryonic whorls are tan, as are the next
three or four apical whorls, which have nearly white, crenulated ribs
along the outer edge. Whorls 13.3-16.3 (15.2 in holotype). Embryonic
whorls 2.3-3.1 (2.7 in holotype); protruding and nipple-shaped. The


Vol. XV







1971 I-HOM\ISON MEXICAN LAND SNAILS 285

fii s two erbrir onic whot Is (lig. I, H) a e sculptuL ed with rninntc gri.-
ilations. The followinTg oine-hall whol oi so is crossed bl, verl lint
[h ad l Cblts \t til tio grle iito the costiulate seulptuii of thle suc-
ceeding poslenii bi ony \ie oil The fii st .3-4 postiminl)ion]c h oils form
a low domreshaped apex The 4th through the 8th postemb yoncm
whorls arn scalarifoilm and forn the widest part of the shell. The tbllow
mg whomls are flat-sided, while the aperture is extended forward from
the bodv wholl on a moderatel)-long neck The neck is ncally round,


D E
Ficir 7. ( Illo nuni rl ldii lne species. A Holotype B-E. PLiaLtyp(S.






BULLETIN FLORIDA STATE MUSEUM


being weakly compressed on the dorsal surface. The postembryonic
whorls are sculptured with strong, close, slightly oblique and arched
axial ribs, which on the apex form weak nodes or crenulations along the
lower ends. There are 50-64 ribs on the penultimate whorl (51 in holo-
type). The ribs become sharp and irregular on the neck of the aperture,
and hardly extend onto the base of the last whorl. The aperture is irreg-
ularly ovate in hape. Internally it is pinched at the posterior corner. The
peristome is moderately-reflected, being widest along the basal and
columellar margins and narrowest around the posterior corner. The axis
is about one-third the diameter of the shell. It is widest in the apex and
becomes greatly reduced in the whorl. Within each whorl it is spindle-
shaped and bears irregular, slightly oblique thread-riblets. There are
about 25 riblets per whorl near the center of the spire and they are
spaced about 5/mm.
Length of shell 11.2-15.0 mm (13.9), width 4.5-5.3 mm (5.0),
aperture height 2.5-2.8 mm (2.7), aperture width 2.6-2.9 mm (2.8).
Measurements in parenthesis pertain to holotype.
TYPE LOCALITY.-Oaxaca, 1.3 mi. NE of Tonala, 5000 ft. elev.
Snails were collected at the base of a limestone hillside among clusters
of a small fern growing on the stone in slightly damp areas. HOLO-
TYPE: UF 20905, collected 4 July 1966 by my son, Richard L. Thomp-
son, after whom the species is named. PARATYPES: UF 20906 (50);
Dept. Zoologia, Instituto Politecnico Nacional, Mexico (5); same data
as the holotype.
REMARKS.-This snail is unlike any other known species. Its com-
pact claviform shape, sculpture, scalariform whorls, and open umbilicus
serve to distinguish it from all others. It is similar in appearance to C.
adria (Bartsch), but that species differs by having more crowded and
less distinct sculpture on the shell, by having a narrowly perforate umbil-
icus, by having juxtaposed whorls instead of being scalariform along
the apex, and by lacking crenulations along the outer edge of the apical
whorls (Bartsch, 1926: 2). Unfortunately C. adria is known only from
two specimens recovered from river drift along the Rio Balsas at
Balsas, Guerrero. C. richardi is also similar to C. notogastor. Differ-
ences between the two are discussed under the latter species.
Similarities between C. richardi and C. bembix in the scalariform
apical whorls are overshadowed by the many other differences that
characterize C. bembix, including the smooth columella. Similarities
between C. richardi and C. leucostoma are discussed above.
Coelostemma notogastor new species
DIAGNOSIS.-A narrowly umbilicate, medium-sized species (about


Vol. XV






1971 THOMPSON MEXICAN ILAN) SNAILS 287

12-16 mm long) of cAlIidiicad- pupo, l shd e ha Thl e spin is modelatel]
extended ith t(\o pilot ilding, tlcescopeld rnill)ionie I ioi\ ls that aii
sculptured ~ Ith line gtanules. "llie I maiiiing wv1orls ale s iulptui d
with closel -spaced, ,ar hed th icd-ri hlcts. I'he apeitmi' cIxlind fci-
wai d on a shoi nI Iek. The axis bteas a slight shimed iln swell g and is
sculptuied with il gnaI., corlsc, obliIquc Iblds

SliniL (Fig. 8, A-E). -The shell is mncdur-si/ed hlic lowr por-
tion is nearly vl ndrn aIl \ hilr tie tie spi is' moderatly iatteiiiate, weak-


A B


D E
Fici-T 8, CS(ohr ltn n;okl( oa nr\\ species A IIlctype B E PaiLtipes






BULLETIN FLORIDA STATE MUSEUM


ly convex in outline, and bears 2.3-2.8 protruding embryonic whorls
(2.5 in holotype) that appear to be telescoped. The umbilical perfora-
tion is narrow and elliptical. The shell wall is moderately thick, subtrans-
lucent when fresh, and dull fleshy-gray in color. Whorls 14.7-18.3
(17.0 in holotype). The embryonic whorls are sculptured with minute
granules (Fig. 1, G). The last quarter of the second embryonic whorl
bears fine, irregular threads that grade into the riblets on the succeed-
ing whorl. The post embryonic whorls are sculptured with fine, close
thread-riblets that are coarsest on the spire and the last whorl and weak-
est on the cylinder of the shell. The riblets on the spire tend to form nod-
ules at their bases. The apical whorls are weakly arched, while the re-
maining whorls are only slightly curved. The lower two or three whorls
are slightly reduced in size, the last ending in a short neck. The base of
the last whorl and the neck are rounded. The aperture is subovate in
shape with a flattened parietal margin and a slight protruberance
from the upper lip. The interior of the aperture is broadly auriculate
in cross-section. The peristome is weakly reflected along the upper lip
and broadly so along the basal-columellar corner, where it appears to
be drawn downward. The axis is about a third the diameter of the shell
and is nearly uniform in width, except in the last whorl where it is mark-
edly constricted. It bears a hollow, submedian spiral bulge within each
whorl. The axis is sculptured with irregular, oblique, broken axial rib-
lets between the roof of the whorls and the swelling.
Length of shell 12.0-16.4 mm (13.9), width 3.7-4.3 mm (4.1), aper-
ture height 2.3-2.7 mm (2.6), aperture width 2.3-2.7 mm (2.4). Meas-
urements are based on the type series, those in parenthesis pertain to
the holotype.
The shell shows slight variation among the five population
samples examined. Some specimens of other populations are larger
than the measurements given for the type series, but broad overlap oc-
curs between all samples. Some individuals from other samples also
are claviform, but such specimens are exceptional.
TYPE LOCALITY.-Oaxaca, a limestone hill 14.2 mi. SW of Sola de
Vega, 6500 ft. elev. HOLOTYIPE: UF 20910, collected 13 September,
1967 by Fred G. Thompson. PARATYPES: UF 20909 (35); Dept.
Zoologia, Instituto Politecnico Nacional, Mexico (5); same data as the
holotype.

OTHER LOCALITIES.-OAXACA:- 15.2 mi. SW of Sola de Vega, 6400 ft. elev.
(UF 20922. 26); 5.7 mi. SW of Sola de Vega, 6300 ft. elev. (UF 20923. 75); 0.7
mi. S of Tlapacoyan, 5000 ft. elev. (UF 20921. 17); 4.9 mi. SSW of Tlapacoyan,
6100 ft. elev. (UF 20924. 24).


Vol. XV






THOMPSON: MEXICAN LAND SNAILS


ECOLOGICAL NoTEs.-Snails were moderately common at all local-
ities. At the type locality they were found under limestone blocks in a
submesic oak forest. At other localities they were found under lime-
stone rubble and caliche in submesic vegetation consisting of either
dwarf oaks or grasses. These habitats are not so xeric as those occupied
by other species of the genus.
REMARKS.-This is the southern most known member of the genus.
It is closely related to C. richardi Thompson as is suggested by similar-
ities in the embryonic whorls, size, sculpture, and the open umbilicus.
It differs from the latter by its general shape, finer sculpture, more
attenuate spire, non-scalariform apex, spiral swelling on the axis, and
coarser sculpture on the axis. The two species differ also in the shape
and internal contour of their apertures as is described for each. C. noto-
gastor also bears a similarity to C. fusca (Martens) in general appear-
ance. C. fusca is readily differentiated by its smooth spindle-shaped
axis, more attenuate spire, smooth-striate whorls, broader umbilicus,
and smaller aperture.
ETYMOLOGY.-The name notogastor from the Greek notos, mean-
ing south, and agastor, a near kinsman, refers to the geographic dispo-
sition of the species in relation to the rest of the genus.

Crycoryne new subgenus

TYPE SPECIES: Coelostemma astraxis new species.
The subgenus is distinguished from all other Holospirinae by having
smooth embryonic whorls and large, hollow, nodular spines on the
large, hollow axis. The character of the embryonic whorls relates Cry-
coryne to Styloptyx and Apcrtaxis the only groups of this subfamily
that lack embryonic sculpturing. The axis is unlike that of any other
genus or subgenus within the Holospirinae.

ETYMOLOGY.-The name Crycoryne is derived from the Greek
kryptos, meaning hidden, and koryne, meaning a mace or war club and
alludes to the characteristic axis of the subgenus. The name is of the
feminine gender. The subgenus is monotypic.

Coelostemma (Crycoryne) astraxis new species

DIAGNOSIS.-A large species of Coclostemma readily distinguished
from all others by its series of large nodular spines on the axis. It is also
characterized by the combination of characters consisting of its large






BULLETIN FLORIDA STATE MUSEUM


D E
FIGURE 9. Apical sculpture of Coclostenmma and Mehtalstoima, A. C. (Crycoryni')
astrajxis new species holotypee). B. C. (Apertaxis) coahuilulnis (Bartsch) (holo-
type). C. MAltastoma roc'ncri (Pfeiffer). D. C. (Styloptyx) fortnx new species
holotypee). E. C. forinx ix new subspecies holotypee).


size, its nearly smooth cylindrical whorls, its protruding embryonic
whorls, and its quadratic aperture.

SHELL (Fig. 10, A-E).-Moderately large (about 20-26 mm long)
and cylindric conical in shape. The umbilicus is narrowly perforate.
The shell is highly variable in obesity. Most specimens are more slender
than the holotype (Fig. 10, A) and some individuals tend to be clavate
in shape through reduction in size of the last few whorls. The shell is
opaque and faint pinkish-white in color. Mature shells contain 17.8-21.5
weakly-arched whorls (18.5 in holotype). There are 2.1-3.0 embryonic
whorls (2.2 in holotype) that protrude and are larger in caliber and
width than the succeeding neanic whorl. The embryonic whorls are
round, are separated by a deep suture, and are smooth (Fig. 9, A). The
following 10 whorls gradually increase in size to the width of the shell
and are slightly scalariform. The remaining whorls are nearly uniform
in diameter, with the last two whorls slightly decreasing in width. The
postembryonic whorls on the conical portion of the spire are sculptured
with oblique low riblets that become obsolete at about the 10th
whorl. The earlier whorls have about three ribs per mm. The cylindric


Vol. XV







ITI7 ['I11IPSON M\EXICAN IAW\ SNAIlS 291


0 E


FIGRLR 10 Col)soriemmi ac str a xli t pr A p)Cle A Ilolotyp'c B I. IPa ty s







BULLETIN FLORIDA STATE MUSEUM


portion of the shell is nearly smooth with irregular, fine, incremental
striations. The last whorl or two have low, relatively widely-spaced
ribs that become more distinct and crowded near the peristome. The
aperture is extended forward so that the peristome is free from the pre-
ceding whorl. The neck of the last whorl is irregularly rounded on the
base. The aperture is quadratic in shape and is about as wide as high.
The parietal wall of the aperture forms a strong angle with the columel-
lar wall. The corners of the peristome are weakly angular. The basal
margin is rounded. The peristome is moderately reflected around the
aperture. It is most widely expanded along the basal and columellar
margins and is least expanded along the outer lip. The axis is broad and
hollow, about one-third the diameter of the shell, and bears about 5-6
large, obliquely-compressed and bluntly-pointed nodes per whorl. The
interior of the axis is indented under the corresponding nodes. The
nodes are more numerous and sharper in the conical portion of the
spire.
Length of shell 20.2-26.0 mm (22.8), width 6.7-8.0 mm (8.0), aper-
ture height and width 4.1-4.9 mm (4.9). Measurements in parenthesis
pertain to holotype.
GEOGRAPHIC VARIATION.-This species is known from two places,
the type locality and a hill about 18 miles WSW of the type locality.
Specimens from the second location are nearly inseparable from the
type series. They have slightly fewer whorls (17.1-18.2), and they tend
to be more pupiform. Considerable overlap occurs in both of these
characters.
TYPE LocAILITY.-Durango, 9.0 mi. SSW of Picardias, 4400 ft.
elev. (Picardias is a small town about 30 miles south of Torreon,
Coahuila, and lies just west of the Durango-Coahuila state line). HOLO-
TYPE: UF 20903, collected 28 December 1969 by Fred G. Thomp-
son. PARATYPES: UF 20902 (30); Direccion General de la Fauna
Silvestre, Mexico (4); same data as the holotype.

OTHER LOCALITIES.-DURANGO:- 3.1 mi. SW of Pedricefia, 5000 ft. elev.
(UF 20904).

REMARKS.-This species is unique within Coelostemma be-
cause of the nodose ornamentation on the axis. This feature differs so
much from other types of axial sculpture in the genus that subgeneric
rank is accorded this species.
In superficial aspect this snail is similar to the species described
below from adjacent areas to the northwest. It differs in external char-
acters most consistently by its weakly-arched whorls, by its protrud-


Vol. XV







THOMPSON: MEXICAN LAND SNAILS


ing embryonic whorls, and by its quadratic aperture as well as by its
profound axial differences.
ETYMOLOGY.-The specific epithet astraxis is derived from the
Greek astron, a star, and axon, an axis, and alludes to the appearance
of the axis in cross-section of the shell.

Styloptyx new subgenus

TYPE SPECIES: Coelostemmafornax new species
A subgenus of Coelostemma consisting of species that bear two
spiral lamellae upon the axis of the shell. One lamella is large and oc-
cupies about the lower five whorls, where it lies upon the center of the
axis. The second lamella is very much reduced in size, is confined to
the last whorl, and lies between the first lamella and the floor ofthe whorl.
The subgenus is also peculiar in having two large, smooth embryonic
whorls, the second of which is partially and obliquely submerged be-
neath the adjacent whorls.
The subgenus is known to include one species containing two sub-
species. The species has been collected from a small area in eastern
Durango near Torre6n, Coahuila and extends over a NNE-SSW dis-
tance of at least 50 miles.
ETYMOLOGY.-From the Greek styles, a column, and ptyx, a com-
pressed fold. The name Styloptyx is of the feminine gender.

Coelostemma (Styloptyx)fornax new species

DIAGNOSIS.-The distinguishing characteristics are the same as
those of the subgenus, which includes the two spiral lamellae on the
axis and the oblique embryonic whorls. The typical subspecies is dis-
tinguished by having distinct oblique ribs on all of the postembryonic
whorls and by having nearly flattened whorls.
SHELL (Fig. 11, A-E).-Moderately large (about 17-23 mm long)
and moderately slender. The shell is cylindrical with an apical cone
that gradually increases in diameter to the maximum width of the shell
at about one-third or one-fourth of the distance from the apex. The
lower whorls near the aperture are slightly reduced in diameter. The
shell is opaque and light tan with oblique white ribs. The 16.1-20.2
whorls (19.3 in holotype) are slightly arched at their periphery and
have a moderately-impressed suture. The base of the last whorl is ir-
regularly rounded but tends to be impressed along the outer wall. The
umbilicus is narrowly perforate. The 1.9-2.5 embryonic whorls (2.3 in
holotype) lie at an oblique angle to the axis of the shell so that a portion







BULLETIN FLORIDA STATE MUSEUM


D E
FicLrI, ] L ('iiilC\ truini furni nen species, A. IHlotype. B E. Paratypes.


Vol XV






THOMPSON: MEXICAN LAND SNAILS


of the second embryonic whorl is suppressed below the adjacent volu-
tions and appears reduced in size. The embryonic whorls are smooth
(Fig. 9, D). The succeeding whorls are crossed with oblique, slightly-
arched axial ribs that are of nearly uniform intensity and are about
equally spaced through the length of the shell. The 15th whorl has
49-77 ribs (49 in holotype) that are spaced about 3 per mm. The ribs on
the last whorls become stronger and closer near the aperture. The aper-
ture usually is free from and advanced beyond the preceding whorl. It
is irregularly ovate in shape and generally is as wide as, or wider
than, high. The interior of the aperture is made subtriangular by the
angle formed by the parietal wall and columellar wall. The peristome is
moderately reflected around the aperture. It is most expanded along
the columellar and basal lips and least so along the upper-outer lip.
The axis is large and hollow and is almost one-half the diameter of the
shell near the middle of the spire. The axis is widest in the conical apex
and gradually tapers to the width of the narrow umbilical perforation
in the last whorl. The axis bears two spiral lamellae. The upper lamella
usually occupies the last five whorls, is located just below the middle
within each whorl, and is usually higher than wide. The second la-
mella is confined to the last whorl where it lies midway between the
first lamella and the floor of the whorl. Generally it is narrower and
lower than the first lamella. Neither lamella is evident within the aper-
ture. In addition to the lamella, the axis shows irregular, oblique
white streaks that are incremental lines of growth.
Length of shell 17.5-23.0 mm (21.1), width 5.4-6.9 mm (6.3), aper-
ture height 3.3-4.1 mm (3.8), aperture width 3.4-4.4 mm (4.0). Meas-
urements in parenthesis pertain to the holotype.
GEOGRAPHIC VARIATION.-A series of 39 specimens was collected
on a limestone hill on the opposite side of the valley from the type local-
ity, a distance of about 5 miles NNE. Specimens of this series tend to
be larger and are less conspicuously ribbed, but they show no charac-
teristics by which they can be consistently separated from the type
series.
TYPE LOCALITY.-A limestone mountainside 2.2 miles S of the
Presa Francisco Zarca, Durango; 4100 ft. elev. (The Presa Francisco
Zarca is a dam on the Rio Nazas about 25 mi. SSE of Le6n Guzman
and about 12 mi. NE of Pedricefia, and is about 5 mi. N of the Torre6n-
Durango Highway). The type locality lies at the base of a long high
mountain ridge where snails were collected from under boulders and
cactus in a talus slope. The area is extremely hot and dry, with only
sparse, low, thorny vegetation. HOLOTYPE: UF 20895, collected 26
December 1969 by Fred G. Thompson. PARATYPES: UF 20898







BULLETIN FLORIDA STATE MUSEUM


(25); Direccion General de la Fauna Silvestre, Mexico (8); same data
as the holotype.

OTHER LOCALITIES.-DURANGO:- limestone hill 5.5 mi. S, 1.8 mi. E of
the Presa Francisco Zarca, 4200 ft. elev. (UF 20897).

REMARKs.-This species belongs to a group characterized by spiral
axial lamella and oblique embryonic whorls. Two forms are known to
belong to the group, C. fornax and the subspecies described below. C.
fornax differs from the latter by possessing distinct axial ribs through-
out the length of the shell. It also tends to be shorter and stockier, al-
though these last characters are not consistently distinctive.
ETYMOLOGY.-The specific epithet fornax, taken from the Greek
deity Fornax, the goddess of ovens, alludes to this snail's sun-scorched
habitat.

Coelostemmafornax ix newpecies

DIAGNOSIS.-A form presumed to be subspecifically related to C.
Fornax because of the similarity of all parameters of the shell except
sculpture and whorl contour. Its sculpture differs from that offornax by
having weak incremental striations on the whorls of the cylindric portion
of the spire in contrast to the distinctly ribbed whorl offornax. The con-
tour of its whorls differs by being more noticeably arched.

SHELL (Fig. 12, A-E).-Moderately large (about 20-26 mm long).
The shell is cylindrical or elongate pupiform in shape. It is opaque, dull,
and pinkish-white. There are 17.1-21.0 whorls (19.6 in holotype). The
conical apex consists of 1.8-2.5 embryonic whorls (2.1 in holotype)
and about 5 postembryonic whorls. The embryonic whorls are smooth
and oblique (Fig. 9, E). The following 4-5 whorls are crossed by
numerous, fine, oblique riblets that become crowded and indistinct
with increasing whorl size. The whorls in the cylindrical portion are
arched, nearly smooth, and crossed by irregular, fine, oblique striations.
The last two or three whorls are reduced in size. The last one or two
whorls have low widely-spaced riblets that become strongest on the
periphery of the last whorl near the neck of the aperture. The neck is
rounded on the base. The umbilicus is narrowly perforate. The aper-
ture extends forward on a short neck, is broadly ovate or irregularly
triangular in shape and usually is wider than high. The parietal wall of
the aperture forms an obtuse angle with the columellar wall. The peri-
stome is free from the preceding whorl and is moderately reflected.


Vol. XV





1971 THOMPSON MEXICAN LAND SNAILS 297


A B


D E
FIGURE 12. .Nutti cmmnt ftr irx nerw bubspcies. A Ilolotype B-E. Paratypes.







BULLETIN FLORIDA STATE MUSEUM


Heretofore Metastoma has been treated as a subgenus of Holospira,
an allocation that also has been used for most other related genera. The
large hollow axis of Metastoma is similar to that of Coclostcnma and
indicates a close phylogenetic relationship. This character contrasts
strongly with the thin, solid, lamellate axis of Hlolospira. The presence
of a strong, compressed, angular fold within the aperture is unique to
Metastoma among the Holospirinae and is herein considered sufficient
basis for generic separation. The genus is monotypic. The character-
istics of the apical sculpture described below for M. roemeri are more
similar to that of the typical subgenus of Coclostcmma than to Crycoryne
or Styloptyx and indicate a phylogeny with the former subgenus.

Metastoma roemeri (Pfeiffer)
Cylindrella roemeri Pfeiffer, 1848; Monogr. Helicorum Viventium, 2: 382. (Type
locality: around New Braunfels, Comal County, Texas).
Iloloispira romnri (Pfeiffer), W. G. Binney, 1878; Terr. Moll., 5: 177, fig. 85.-
Pilsbry, 1903; Man. Conch., II, 15: 97-98; pl. 25, figs. 1-7.- Pilsbry, 1905; Proc.
Acad. Nat. Sci. Phila.,: 220; pl. 26, figs. 10-18.- Bartsch, 1906; Proc. U. S. Nat.
Mus., 31: 148.- Pilsbry, 1946; Land Moll. N. Amer., II(1): 114-115; fig. 55.
Holospira roemeri var. minor Cockerel, 1898; Nautilus, II: 136.
This species is widely distributed through southwestern Texas and
southern New Mexico (Pilsbry, 1946: 115). The first 2,' embryonic
whorls have minute granular sculpture (Fig. 9, C). The following t4
embryonic whorl has very weak vertical threads that become more in-
tense near the first postembryonic whorl.
APPENDIX
Specific and subspecific names referred to Coclostemma are listed below with
their current systematic allocations.
adana Bartsch, (Holospira), 1926; Proc. U. S. Nat. Mus., 70: 3; pl. 1, fig. 14. (Type
locality: streamdrift from the Rio Balsas, Balsas Station, Guerrero). = C. (C.)
adana (Bartsch).
adria Bartsch, (Holospira), 1926; Proc. U. S. Nat. Mus., 70; 2-3; pl. 1, fig. 1. (Type
locality: streamdrift from the Rio Balsas, Balsas Station, Guerrero). = C. (C.)
adria (Bartsch).
amplaxis Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105: 159-160; pl. 3, figs. 3-3b.
(Type locality: Sierra Guadaloupe, back of Hacienda Guadaloupe, 7500-
8000 ft. alt.). = C. (Apertaxis) coahuilensis (Bartsch).
anaclasta new species. (Type locality: 1.9 mi. NE of Tecolapa, Colima; 700 ft.
alt.).
anconai Bartsch, 1951; Jour. Wash. Acad. Sci., 41: 146; figs. 1, 3. (Type locality:
Ixcaptiopan, Guerrero). = C. (C.) anconai Bartsch. May be a subspecies of C.
(C.) bourgeoisana Bartsch.
antricola Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 58; fig. 5. (Type locality:
Las Grutas, Cacahuamilpa, Guerrero). = C. (C.) bourgeoisana antricola
Bartsch.


Vol. XV







THOMPSON: MEXICAN LAND SNAILS


astraxis new species. (Type locality: 9.0 mi. SSW of Picardias, Durango; 4400 ft.
alt.).
balesi Pilsbry, 1954; Nautilus, 65: 82; pl. 8, fig. 4. (Type locality: Km. 175, near
Chilpancingo, on road to Acapulco, Guerrero). = C. (C.) balesi Pilsbry.
balsalscsis Bartsch, (Jlolospira), 1926; Proc. U. S. Nat. Mus., 70: 1-2; pl. 1, fig.
16. (Type locality: streamdrift from the Rio Balsas, Balsas Station, Guerrero).
= C. (C.) balsasensis (Bartsch).
bembix new species. (Type locality: 12.6 mi. N of Zumpango del Rio, Guerrero;
2300 ft. alt.).
bourgcoistan Bartsch, 1942; Jour. Wash. Acad. Sci., 32: 187; fig. 1. (Type local-
ity: Ixtapan de la Sal, Mexico). = C. (C.) bourgeoisain bourgeoisaia Bartsch.
bryantwalkcri Pilsbry, 1917; Naut., 30: 124-125; pl. 4, fig. 6. (Type locality': Rio
Conchos, Chihuahua); Subgeneric status uncertain.
chilpancingensis Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105: 158; pl. 5,
figs. 2-3a. (Type locality: between Chilpancingo and Mazatlan, Guerrero). = C.
(C.) chilpancingcnsis Pilsbry.
clavifoirmis Martens, (Ilolospira), 1897; Biologia Centrali Americana: 277; pl.
16, figs. 10-16. (Type locality: Amula, Guerrero). = C. (C) elizabethae (Pilsbry).
coahuilensis Bartsch, (Epirobia), 1906; Proc. U. S. Nat. Mus., 31: 121; pl. 4, fig.
3. (Type locality: Sierra Guadaloupe, Coahuila). = C. (Apcrtaxis) coahuilensis
(Bartsch).
dalli Pilsbry, (Ilolospira), 1903; Man. Conch., Ser. II, 15: 100-101; pl. 26, figs.
28-31. (Type locality: Sierra de Guadaloupe, Coahuila). = C. (C.) dalli (Pilsbry).
eclipes new species. (Type locality: 16.4 mi. N of Zumpango del Rio, Guerrero;
2300 ft. alt.).
elizabethac Pilsbry, 1889; Proc. Acad. Nat. Sci. Phila.: 81; pl. 3, figs. 1-5. (Type
locality: Amula, Guerrero). = C. (C.) elizabethae (Pilsbry).
fornax new species. (Type locality: 2.2 mi. S of the Presa Francisco Zarca, Du-
rango; 4100 ft. alt.).
fr'ytagi Bartsch, 1950; Jour. Wash. Acad. Sci., 40: 265; fig. 1. (Type locality:
Chihuahuan desert, 29 mi. W of Jimenez, Chihuahua). Subgeneric status un-
certain.
fusca Martens, (Holospira), 1897; Biologia Centrali Americana: 281; pl. 16, figs.
20-24. (Type locality: Omilteme, Guerrero). = C. (C.)fusca (Martens).
greggi Drake, 1951; Revista de la Sociedad Malacologica, 8: 40-41; pl. 6, figs.
3-4. (Type locality: foothills of the Sierra de Almoloya, near Cuevo Diablo,
near Salaices, Chihuahua). = Holospira (Haplocion) greggi (Drake).
hazelae Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105: 159; pl. 5, fig. 4. (Type
locality: between Chilpancingo and Mazatlan, Guerrero). = C. (C.) hazcela
Pilsbry.
hcrrcrae Bartsch, (Ilolospira), 1906; Proc. U. S. Nat. Mus., 31: 150, pl. 4, fig.
14. (Type locality: Silaca Yuapan [Silacayoapan], Oaxaca). = C. (C.) hlurrerae
(Bartsch).
iqualaensis Bartsch, (Holospira), 1926; Proc. U. S. Nat. Mus., 70: 3, pl. 1, fig. 12.
(Type locality: Iquala [Iguala], Guerrero). = C. (C.) iqualaensis (Bartsch).
imbricate Martens, (Cylindrclla), 1863; Monatsber. Berl. Akad. Wissensch.: 540.
(Type locality: Mexico). = C. (C.) imbricata (Martens).
ix new subspecies. (Type locality: 1.0 mi. E of Dinamita, Durango; 4900 ft. alt.).
leucostoma new species. (Type locality: Ruinas de Xochicalco, Morelos; 4900 ft.
alt.).







BULLETIN FLORIDA STATE MUSEUM


lichcnophora Bartsch, (Ilolospira), 1906; Proc. U. S. Nat. Mus., 31: 146-147; pl.
4, fig. 7. (Type locality: Encarnacion, Hidalgo). = C. ((.) liclihniphora (Bartsch).
lissocentrum Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105: 158-159; pl. 8, figs.
5-5b. (Type locality: Cerro Potosi, Nuevo Le6n; 10,000 ft. alt.). = C. (C) lis-
socentrum Pilsbry.
marrsi Drake, 1951; Revista de la Sociedad Malacologica, 8: 39-40; pl. 6, figs.
1-2. (Type locality: Cuevo Diablo, near Salaices, Chihuahua). Subgeneric
status uncertain.
microstoma Pfeiffer, (Cylindrclla), 1861; Proc. Zool. Soc. London: 27. (Type lo-
cality: unknown). Status uncertain; may be a species of Coelost.emma (Coelo-
stcm ma).
notogastor new species. (Type locality: 14.2 mi. SW of Sola de Vega, Oaxaca;
6500 ft. alt.).
prcsidioensis Bartsch, 1943; Jour. Wash. Acad. Sci., 33: 58-59; fig. 2. (Type lo-
cality: Presidio, Veracruz). = C. (C) presidioensis Bartsch.
reitcri Drake, 1951; Revista de la Sociedad Malacologica, 8: 41-42; pl. 6, figs. 5,
6. (Type locality: Los Remedios, Distrito Jim6nez, Chihuahua). Subgeneric
status uncertain.
richardi new species. (Type locality: 1.3 mi. NE of Tonalh, Oaxaca; 5000 ft. alt.).
saltillensis Pilsbry, 1953; Proc. Acad. Nat. Sci. Phila., 105: 157-158; pl. 5, figs.
5-5c. (Type locality: mountains on the right of the highest pass on road from
Saltillo to Diamonte, Coahuila, 7900 ft. alt.). = C. (C.) saltillensis Pilsbry.
strcbcliana Pilsbry, (Ilolospira), 1903; Man. Conch., 15: 101; pl. 26, figs. 24-28.
(Type locality: Sierra de Guadaloupe, Coahuila). = C. (C.) dalli (Pilsbry).
townsendi Bartsch, (llolospira), 1906; Proc. U. S. Nat. Mus., 31; 145-146;
pl. 4, fig. 13. (Type locality: Cerro Chilicote, Chihuahua). Subgeneric status
uncertain.
Five species, bryantwalkeri, freytagi, marrsi, reiteri, and totwnsendi, com-
prise a natural assemblage that probably merits subgeneric recognition. This
group will be discussed elsewhere.

LITERATURE CITED
Bartsch, Paul.
1906. The Urocoptid Mollusks from the Mainland of America in the Col-
lection of United States National Museum. Proc. U. S. Nat. Mus., 31:
109-160; pls. 3-5.
1926. New Urocoptid Land Shells from Mexico. Proc. U. S. Nat. Mus., 70:
1-13; pl. 1.
Martens, Eduard von.
1890-1901. Biologia Centrali Americana: Land and Freshwater Mollusca.
London. 706 pp, 44 pls.
Pilsbry, Henry A.
1889. New and Little-known American Molluscs. No. 1. Proc. Acad. Nat.
Sci. Phila.; 81.
1902-1902. Manual of Conchology, Ser. II, 15: 1-323; pls. 1-65. Philadelphia.
1946. Land Mollusca of North America, 2(1): i-vi, 1-520. Philadelphia.
1953. Inland Mollusca of Northern Mexico. II. Urocoptidae, Pupillidae,
Strobilopsidae, Valloniidae and Cionellidae. Proc. Acad. Nat. Sci.
Phila., 105: 133-167; pls. 3-9.


Vol. XV




_70. 73






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