• TABLE OF CONTENTS
HIDE
 Front Cover
 Copyright
 Abstract
 Table of Contents
 Introduction
 Acknowledgement
 The molluscan fauna
 Helicinidae
 Annulariidae
 Pupillidae
 Subulinidae
 Bulimulidae
 Urocoptidae
 Sagdidae
 Polygyridae
 Literature cited
 Back Cover






Group Title: Bulletin of the Florida State Museum
Title: A Review of the land snails of Mona Island, West Indies
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00095796/00001
 Material Information
Title: A Review of the land snails of Mona Island, West Indies
Series Title: Bulletin - Florida State Museum ; volume 31, number 2
Physical Description: p. 67-106 : ill., map ; 23 cm.
Language: English
Creator: Thompson, Fred G ( Fred Gilbert ), 1934-
Florida Museum of Natural History
Donor: unknown ( endowment )
Publisher: Florida State Museum, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1987
Copyright Date: 1987
 Subjects
Subject: Gastropoda -- Classification   ( lcsh )
Gastropoda -- Puerto Rico -- Mona Island   ( lcsh )
Mollusks -- Classification   ( lcsh )
Mollusks -- Puerto Rico -- Mona Island   ( lcsh )
Genre: bibliography   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Spatial Coverage: Puerto Rico
 Notes
Bibliography: Includes bibliographical references (p. 105-106).
General Note: Cover title.
General Note: Abstract in English and Spanish.
Statement of Responsibility: Fred G. Thompson.
 Record Information
Bibliographic ID: UF00095796
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: oclc - 15702341

Table of Contents
    Front Cover
        Page 67
    Copyright
        Page 68
    Abstract
        Page 69
    Table of Contents
        Page 70
    Introduction
        Page 71
        Page 72
    Acknowledgement
        Page 73
    The molluscan fauna
        Page 74
        Page 75
    Helicinidae
        Page 76
        Page 77
        Page 78
        Page 79
        Page 80
    Annulariidae
        Page 81
        Page 82
    Pupillidae
        Page 83
    Subulinidae
        Page 84
        Page 85
        Page 86
    Bulimulidae
        Page 87
        Page 88
    Urocoptidae
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
    Sagdidae
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
        Page 99
        Page 100
    Polygyridae
        Page 101
        Page 102
        Page 103
        Page 104
    Literature cited
        Page 105
        Page 106
        Page 107
    Back Cover
        Page 108
Full Text









of the
FLORIDA STATE MUSEUM
Biological Sciences
Volume 31 1987 Number 2





A REVIEW OF THE LAND SNAILS OF MONA ISLAND,
WEST INDIES


FRED G. THOMPSON


UNIVERSITY OF FLORIDA


GAINESVILLE







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







OLIVER L. AUSTIN, JR., Editor
S. DAVID WEBB, Associate Editor
RHODA J. BRYANT, Managing Editor



Consultants for this issue:

ARTHUR BOGAN
W. LLOYD PRATT








Communications concerning purchase or exchange of the publications and all manuscripts
should be addressed to: Managing Editor, Bulletin; Florida State Museum; University of
Florida; Gainesville FL 32611; U.S.A.


Publication date: 30 January 1987


This public document was promulgated at an annual cost of $2220.00 or
$2.22 per copy. It makes available to libraries, scholars, and all interested
persons the results of researches in the natural sciences, emphasizing the
circum-Caribbean region.


Price: $2.25












A REVIEW OF THE LAND SNAILS

OF MONA ISLAND, WEST INDIES


FRED G. THOMPSON*




ABSTRACT


The fauna consists of 24 species and subspecies. Nine taxa are endemic to the
island, four are related to species on Puerto Rico, and three are related to species on
Hispaniola. The biogeographic relationships of two are less clear. Thirteen species are
regarded as introduced. The remaining nonendemic native species show mixed affinities
with Puerto Rican and Hispaniolan taxa.
The following new taxa are described from Mona Island: Stoastomops grada new
species, Varicella (Sigmataxis) nesiotes new species, Microceramus stenegrus new species,
Hoieda insularis eurvtrema new subspecies, and Plagioptycha musicola fortisculpta new
subspecies. Hoieda i. insularis new species is described from the satellite island of Monita.
The following is a new name combination: Drymaeus virgulatus beatti for D. elongatus
beatti Clench.


RESUME


La fauna de la Isla Mona consiste de 24 species y subespecies. Nueve taxones
son end6micos a la isla. Cuatro estan emparentados con species de Puerto Rico y tres con
species de Hispaiola. Las relaciones biogeograficas de dos de las species no son muy
claras. Trece species se consideran introducidas. Las restantes species nativas no
end6micas muestran afinidades tanto con taxones de Puerto Rico como de Hispafiola. Se
described los siguientes taxones para la Isla Mona: Stoastomops grada nueva especie,
Varicella (Sigmataxis) nesiotes nueva especie, Microceramus stenegrus nueva especie,
Hoieda insularis eurytrema nueva subespecie, y Plagioptvcha musicola fortisculpta nueva


*The author is Curator in Malacology at the Florida State Museum, University of Florida,
Gaincsvillc FL 32611.


THOMPSON, F.G. 1987. A Review of the Land Snails of Mona Island, West Indies. Bull.
Florida State Mus., Biol. Sci. 31(2):69-106.







70 BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


subespecie. La nueva subespecie, Hoieda i. insularis se describe para la isla sat6lite de
Monita. La siguiente es una nueva combinaci6n: Drvmaeus virgulatus beattvi en vez de D.
elongatus beattyi Clench.


TABLE OF CONTENTS


IN T R O D U CT IO N ..................................................................................... ........................... 70
ACKNOW LEDGEM ENTS........................................................ ............................. 73
THE MOLLUSCAN FAUNA.................................... 73
H elicinidae ............................... ..... .................... .......... 76
A nnulariidae.................. ...................... ............ ........... ........ ..... 81
P upillidae................................ ...... .. ....... ............................. 83
Cerionidae ....................................... ................................. 83
H elicarionidae................................ ........... ................ ............ ... 83
Ferussaciidae ...................... .......................................... ......... 83
Subulinidae .............................. ....... ..... ............................ 84
O leacinidae............................. .................................................... 84
B ulim ulidae............................. ........................... ................... 87
U rocoptidae........................................................ ........................................ 89
Sagdidae .................................................................... ...................................... 94
Polygyridae...................................... ......................................................... 101
X anthonychidae....................... .............................. ........ ...... ........... 101
LITERATURE CITED ................................................... ..... ................ 105


INTRODUCTION


In 1972 studies on the flora, fauna, and mineral resources of Mona
Island were initiated because of proposed economic developments and a
proposed national park on the island (Wadsworth 1975). I visited the island
for four days during May 1974 to survey the land snail fauna. A second visit
of three days was made during November 1978 for the same purpose. Both
visits were at the height of long dry periods, and only dead shells of most
species were found.
Mona Island lies in the Mona Passage about halfway between
Puerto Rico and Hispaniola at 18006'N, 67055'W. It is a small, bean-
shaped desert island about 11 km long by 7 km wide. The island is capped
by the Miocene Lirio Limestone, which is rugged and dog-toothed. This
overlays the middle or lower Miocene Isla de Mona Dolomite (Aaron
1975). The island is bordered on all sides by abrupt cliffs that rise about 45







THOMPSON: MONA ISLAND LAND SNAILS


m high. The island is bounded along its southern and western sides by
narrow Holocene coastal plains that were inhabited by Taino Indians at the
time of Columbus. It has been inhabited intermittently by settlers since
then. Apparently the name of the island is derived from the Taino name
Amona and not from the Spanish mona, meaning monkey (Wadsworth
1975).
The island plateau is covered with a dense submesic scrub thorn
forest similar in floral composition to that of other low-lying limestone
islands in the West Indies (Woodbury 1975). This thorn forest contains
scattered patches of mesic high forest toward the center of the island and a
narrow fringe of low xeric scrub along the north and east edges of the
plateau. The coastal plains generally are covered with submesic thorn
forests. Along the southwestern base of the plateau, near Sardinero
(Station 3), grows a narrow fringe of wet evergreen forest fed by ground-
water seepage from the cliffs.


FIELD STATIONS


Mollusk collections were made at thirteen field stations (Fig. 1). A brief
description of each follows.
STATION 1. Slopes and bluff behind Sardinero, amid limestone boulders and
along cliff. Mesic forest.
STATION 2. Base of limestone cliff at Sardinero in an area with a high mesic
forest.
STATION 3. Base of limestone cliff at Sardinero in high mesic forest with
patches of wet evergreen forest.
STATION 4. Punto Oeste, among grasses over sandy soil on low coastal plain.
STATION 5. Coastal plain near landing field. Snails collected on grasses and
shrubs over sandy soil.
STATION 6. Uvero. Snails collected on grasses and shrubs over sand-gravel
soils in a submesic thorn forest.
STATION 7. Talus slope 1 km E of Uvero in a submesic thorn forest.
STATION 8. Limestone cliffs east of Uvero along road-cut. Area covered with
a dense submesic thorn forest.
STATION 9. Playa Pajaro. A submesic forest with dense thickets of
Manchanilla. Cliffs with clusters of small bromeliads and cactae. Snails were collected
from debris and loose soil at the base of cliff.







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


FIGURE 1.- Map of Mona Island showing major physical fcatutirs, anid s1.,tions Irom
which specimens were collected.







THOMPSON: MONA ISLAND LAND SNAILS


STATION 10. Lirio Lighthouse. Snails collected at night on shrubs and small
trees in submesic forest.
STATION 11. Coral de Los Indios, 1.3 km NE of Lirio Lighthouse. A high mesic
forest.
STATION 12. Bajura de Los Cerezos. A limestone depression with a clay-soil
substrate in a high mesic forest.
STATION 13. Cabo Norte. An area of low sparse xeric scrub on rugged dog-
toothed limestone.
Specimens were also collected along transects from Station 8 to Station 10 and
from Station 10 to Station 12.



ACKNOWLEDGEMENTS



Financial support for field work on Mona Island was provided by the U.S. Fish
and Wildlife Service contracts No. 14-16-0008-785 and No. 85910-0339. Field work in
Puerto Rico essential to this project was sponsored by the Florida State Museum. The U.S.
Coast Guard Service at Aguadilla, Puerto Rico, through arrangements made by the U.S.
Fish and Wildlife Service, provided helicopter transportation to Mona and Monita islands.
The following persons assisted me in field work on Mona Island: Howard W. Campbell,
Steven P. Christman, Ronald I. Crombie, and Thomas A. Wiewandt. George M. Davis
(Academy of Natural Sciences, Philadelphia), Joseph Rosewater (National Museum of
Natural History), and Ruth D. Turner (Museum of Comparative Zoology) loaned me
specimens in their charges and handled other queries relating to this study. The
illustrations of the island map (Fig. 1), and of Microceramus (Figs. 32-36) were skillfully
executed by Nancy Halliday, Gainesville, Florida. Wendy Zomlefer, Florida State Museum,
Staff Artist, rendered the excellent illustrations of Hoieda. Kurt Auffenberg, Florida State
Museum Biologist, produced the SEM photographs used in this paper and did many other
tasks essential for the completion of the project. I am deeply grateful to all of the above
persons for their help.


TIlE MOLLUSCAN FAUNA


The land snail fauna of Mona Island was first reported upon by
Clench (1950), based upon collections made by Harry Beatty and given to
the Museum of Comparative Zoology (Harvard University), and upon
collections made by Paul Bartsch and deposited in the National Museum of
Natural History (Washington, D.C.). Clench recorded 15 species and
subspecies from the island. These are listed below along with the taxa
found during the present survey.








BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


This report


Lucidella umbonata (Shuttl.)
Stoastomops puertoricensis Baker
Chondropoma turnerae Clench




Cerion monaensis Clench
Guppya gundlachi (Pfeiffer)
Habroconus sp.





Lamellaxis micra (Orbigney)



Bulimulus g. guadelupensis (Brug.)
Bulimulus g. evriesi (Drouet)

Drymaeus elongatus beattvi Clench
Brachypodella beattyi Clench
Microceramus guanicanus Baker
Hojeda inaguensis (Weinland)




Hemitrochus gallopovonis (Pfeiffer)
Plagioptycha euclasta (Shuttl.)


= Helicina umbonata pitheca Thompson
= Stoastomops grada new species
= Licina aguadillensis turnerae (Clench)
Gastrocopta rupicola marginalba
(Pfeiffer)
Gastrocopta pellucida (Pfeiffer)
Cerion monaensis Clench
Guppya gundlachi (Pfeiffer)
absent
Cecilioides aperta (Swainson)
Obeliscus sp.
Obeliscus swiftianus (Pfeiffer)
Subulina octona (Brug.)
Lamellaxis micra (Orbigney)
Opeas pumilum (Pfeiffer)
Varicella nesiotes new species
absent
absent
Bulimulus d. diaphanus (Pfeiffer)
= Drymaeus virgulatus beatti Clench
Brachypodella beattyi Clench
= Microceramus stenegrus new species
Hojeda inaguensis (Weinland)
Hoieda insularis eurvtrema new
subspecies
Thvsanophora plagioptycha (Shuttl.)
Hemitrochus gallopovonis (Pfeiffer)
= Plagioptycha musicola fortisculpta new
subspecies


The biogeographic affinities of the Mona Island land snail fauna
are summarized in Table 1. The nine species considered to be introduced
onto the island by humans are mainly small forms, widely distributed in the
West Indies and elsewhere, and characteristically are associated with
tropical fructiculture. Three other species, Habroconus sp., Obeliscus
swiftianus, and Bulimulus d. diaphanus, also may be human-introduced but
are more restricted in their present distribution around Puerto Rico and the
Virgin Islands. The remaining 12 species are considered to be natural


Clench (1950)








THOMPSON: MONA ISLAND LAND SNAILS 75





Table 1. Biogeographic relationships of the land snail fauna of Mona Island.


Puerto Widespread
Species Endemic Rico Hispaniola Introduced


Helicina umbonata pitheca + +
Stoastomops grada + +?
Licina aguadillensis tumerae +
Gastrocopta nrpicola marginalba +
Gastrocopta pellucida +
Cerion monaensis + +
Guppya gundlachi +
Habroconus sp. + ?
Ceciliodes aperta +
Obeliscus sp. + ?
Obeliscus swiftianus +
Subulina octona +
Lamellaxis micra +
Opeas pumilum +
Varicella nesiotes + +
Bulinmuls d. diaphanous + ?
Dtymaeus virgulatus beattyi + +
Brachypodella beattyi + +
Microceranus stenegms + +
lfojcda inaguensis +
Hojeda insularis curytrema +
Thysanophora plagioptycha +
IfHemitrochus gallopovonis +
Plagioptycha musicola
fortisculpta + +







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


inhabitants of the island. Of these, six are endemic species, and three are
endemic subspecies, yielding an endemism of 50% at the species level and
83% at the subspecific level for the native land snail fauna of the island. Of
the endemic taxa, four have systematic affinities to species occurring on
Puerto Rico, three are related to Hispaniolan species, and two are of
uncertain relationships.


HELICINIDAE

Helicina umbonata pitheca THOMPSON

Lucidella umbonata (Shuttleworth), Clench 1950:271; fig. 2.
Helicina umbonatapitheca Thompson 1982:15-17; Figs. 36-43.
The taxonomic status of the Mona Island population of Helicina
umbonata has been discussed recently (Thompson 1982). H. u. pitheca is
distributed ubiquitously on the island. Live specimens commonly are found
aestivating on low shrubs, grasses, and vines. The brightly colored shell is
adaptive for a cryptic existence in this habitat.


Stoastomops grada new species

Stoastomops puertoricensis Baker, Clench 1950:271.
SHELL (Figs. 2-5).-- Small 2.2-2.6 mm wide; 0.81-0.92 times as high
as wide; depressed turbinate-conical with 3.9-4.2 whorls. Two color phases:
one phase citron yellow, other phase light orange holotypee). Whorls
subangular at the periphery and scalariform; flattened or weakly concave
above periphery, convex below, umbilical region nearly flat. Protoconch
(Fig. 10) raised, slipper-shaped, consisting of 3/4 of a turn; 0.37 mm long
and 0.26 mm wide; sculptured with a few weak incremental striations and
irregular, oblique spiral striations. Subsequent half whorl with about 10
fine, raised spiral threads, which continue onto lower whorls where they
become enlarged and are crossed at irregular intervals by oblique varix-like
fimbriations (Fig. 11); 7-10 spiral threads on dorsal surface of last whorl.
Spiral threads below periphery weak, discontinuous, and poorly defined on
base (Fig. 12). Aperture ovate-auriculate in shape; 0.44-0.53 times height of
shell; 0.71-0.80 times as high as wide. Columellar lip conical in







THOMPSON: MONA ISLAND LAND SNAILS


FIGURES 2-9. FIG. 2-5: Stoastomops grada new species, Paratypes (UF 40715) (X
24). FIGS. 6-9: Stoastomops puertoricensis Baker (UF 40714; 7.0 km SE Guanica, Puerto
Rico) (X 24).







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


shape, hollow internally (Figs. 13-15). Outer periphery of columellar lip
angular so that it appears, falsely, to be rimate.
Measurements in mm based on 29 specimens are given below.

n height width aper. h. aper. w. whorls
UF 40678 15 1.9-2.1 2.2-2.6 0.93-1.05 1.24-1.43 4.0-4.2
UF 24989 3 1.9-2.1 2.2-2.4 0.93-0.99 1.19-1.36 4.0-4.2
UF 40677 10 1.9-2.1 2.1-2.4 0.87-0.99 1.24-1.36 4.0-4.1
Holotype 1 1.98 2.17 0.93 1.30 4.1

Specimens from the bluffs near Sardinero generally are larger than
specimens from other localities. This may reflect the more favorable mesic
habitat characterizing that area. Sexual dimorphism in size cannot be
determined from the material on hand, because I found only dead shells on
the two occasions I visited the island.
OPERCULUM (Figs. 16-18).-- Narrower than in S. puertoricensis
Baker (Figs. 19-21). Calcareous plate weakly granular with a low, narrow,
weakly arched ridge closely paralleling the columellar margin (Figs. 17,18).
TYPE LOCALITY.-- Mona Island, Coral de Los Indios, 1.3 km
northwest of the Lirio lighthouse. HOLOTYPE: UF 40676; collected 22
May 1974 by Fred G. Thompson from leaf litter along the base of a low
ledge in a mesic forest. PARATYPES: UF 40677 (49); UF 40719 (SEM
opercula); same data as holotype. Other paratypes from Station 1 (UF
24989, 9 specimens), Station 3 (UF 40678, 30 specimens; UF 40715, 4 SEM
shells), Station 8 (UF 40679, 30 specimens), and Station 9 (UF 40680, 9
specimens). All were found along limestone ledges in leaf litter. Isabella
Anchorage (USNM 430974, 13 specimens).
DISTRIBUTION.-- Endemic to Mona Island.
REMARKS.-- This species is most similar in shape to S. adamsi
Baker from Jamaica. It differs from S. adamsi by its sculpture. S. adamsi
has 6-7 spiral threads above, and 28-29 below on the last whorl (Baker
1934:10; 1935, fig. 1). The threads are weaker than in S. grada and uniform
in size over the surface of the whorl. S. grada is similar to S. puertoricensis
Baker in sculpture, but differs in shape and opercular structure. In S.
puertoncensis the spire is concave-conical with the whorls separated by a
deeply incised suture (Figs. 6-9). The dorsal surface of the whorls usually
has a shallow furrow below the suture (Fig. 8). The operculum is broader
and the calcareous plate bears a thick, wide, straight vertical ridge that is
offset from the columellar margin (Figs. 19-21).





THOMPSON: MONA ISLAND LAND SNAILS


14

-44


15



FIGURES 10-15.- Stoastomops grada new species, Paratypes. FIGS. 10-11: UF 40715
(X 80). FIG. 12: UF 40715 (X 53). FIG. 13: UF 40718 (X 27). FIG. 14: UF 40717 (X 27).
FIG. 15: UF 40717 (X 16).







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


FIGURES 16-21. FIGS. 16-18: Stoastomops grada new species, opercula (UF 40719).
FIGS. 19-21: Stoastomops puertoricensis Baker, opercula (UF 40713, 7 km SE Guanica,
Puerto Rico). (X 53).







THOMPSON: MONA ISLAND LAND SNAILS


Baker (1941:1) stated that the columella of S. puertoricensis
sometimes is rimate (narrowly perforate). This is incorrect. The outer edge
of the columellar lip is angular so that when viewed from the front it
appears to form a rimate opening into the columella. Such a condition does
not exist in the Helicinidae, because the parietal shelf partially forms a short
tube that extends into the columellar lip as a blind caecum (Figs. 13-15). A
perforation would puncture this tube.
Baker (1934:10), on Pilsbry's advice, described S. adamsi as a new
species, although Baker considered it to be synonymous with Helicina tenuis
Adams, September 1849, p. 14. Pilsbry contended that Helicina tenuis
Adams is not an available name, because it is preoccupied by Helicina tennis
Pfeiffer, April 1949, p. 124, not withstanding the fact that Adams (1849:16),
two pages later, placed tenuis Adams in Trochatella. Baker (1935:63)
surreptitiously reverted to the use of Adams name as Stoastomops tenuis
(Adams). The Jamaican species should be referred to as Stoastomops
adamsi Baker.
ETYMOLOGY.-- The name grada is from the Latin gradus, a step or
stairs, and refers to the scalariform step-like whorls.


ANNULARIIDAE

Licina aguadillensis tumerae (CLENCH)

Chondropoma turnerae Clench 1950:271-272, fig..
Licina (Choanopomops) aguadillensis tumerae Baker 1962a:23.
This snail is nearly ubiquitous on Mona Island. It was collected at
all stations except 2 and 5, which are on loose sand. Baker (1962a) referred
populations from Cerro Capron, near Guanica, Puerto Rico, to this
subspecies and places all the Puerto Rican Annulariinae in Choanopomops
Baker 1928. The operculum of tumerae (Figs. 22, 23) is typical of the
subgenus by having on the outer surface a partial carcareous lamella that is
reinforced from beneath by calcareous ribs and deposits. The face of the
underlying chitinous plate is covered with calcareous granules.






BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


24


FIGURES 22-26. FIGS. 22-23: Licina aguadillensis turncrae (Clench), opcrcula (UF
40720). (X 18). FIGS. 24-26: Varicella (Sigmataxis) ncsiotes new species, Paratype (UF
40833). FIG. 24 (X 11). FIG. 25: Sculpture of body whorl at inset in Fig. 24. (X 212). FIG.
26: Sculpture of columella (X 108).







THOMPSON: MONA ISLAND LAND SNAILS


PUPILLIDAE

Gastrocopta nrpicola marginalba (PFEIFFER)

Collected in leaf litter samples from Stations 1 and 3.

Gastocopta pellucida (PFEIFFER)

Collected in leaf litter from Stations 3, 8, 9, and 11.


CERIONIDAE

Cerion monaensis CLENCH

Abundant and generally distributed on the coastal plains along the
south side of Mona Island. Locally distributed on the limestone plateau.


HELICARIONIDAE

Guppya gundlachi (PFEIFFER)

Dead shells were collected in leaf litter at Stations 3, 11, and 12 in
patches of mesic forest. Live snails were found crawling on dead leaves at
Station 3.

Habroconus sp.

Clench (1950:273) recorded two specimens of an apparently
undescribed species which were collected at Isabella Anchorage
(Sardinero). Apparently these are the same as the species common on
Puerto Rico. Habroconus was not found on the island during this survey.
The specimens reported by Clench cannot be located in the Musuem of
Comparative Zoology or the National Museum of Natural History.
Apparently they are lost.

FERUSSACIIDAE

Cecilioides aperta (SWAINSON)

Collected at Stations 1 and 3; sifted from loose humus-rich soil.







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


SUBULINIDAE

Obeliscus swiftianus (PFEIFFER)

Dead shells were recovered from leaf litter at Stations 1, 3, 8, 9, and
12. The species appears to be restricted to mesic forests along the
escarpment on the south side of the island and in a mesic forest at Station
12.

Obeliscus sp.

A single specimen of an unidentified species was collected at
Station 12. It is similar to 0. simpsoni Pilsbry from Hispaniola but is
immature, and specific identification is uncertain.


Subulina octona (BRUGUIERE)

Nearly ubiquitous in terrestrial habitats on the island.


Lamellaxis micra (ORBIGNEY)

Collected in leaf litter at Station 1, 3, and 12 in mesic forest.


Opeas pumilum (PFEIFFER)

Found in leaf litter at Station 3.

OLEACINIDAE

Varicella (Sigmataxis) nesiotes new species

SHELL (Figs. 24, 27-29).-- Very thin, elongate-turrete. Adults
about 0.31-0.34 times as wide as high and proportionally more slender than
juveniles. Spire about 0.60-0.64 times length of shell (0.61 in holotype),
nearly straight-sided in outline. Shell uniformly colored; translucent; axis
twisted internally. Whorls 5.3-5.5 in large specimens (5.0 in holotype);
embryonic shell with 1.8 whorls. Suture deeply impressed and weakly
crenulated by the striate sculpture. Whorls of spire moderately







THOMPSON: MONA ISLAND LAND SNAILS


28 29

0 1 2
mm


FIGURES 27-29.- Varicella (Sigmataxis) nesiotes new species. FIG. 27: Paratype (UF
40832). FIGS. 28, 29: Holotype (UF 40831).







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


arched, very narrowly shouldered along suture. Body whorl in large
specimens may be flattened or even weakly concave peripherally. Periphery
of last whorl slightly below middle of whorl. Embryonic whorls glossy and
smooth. Subsequent whorls sculptured with nearly equally spaced arcuate
transverse striations that are continuous across surface of whorl, about 8-10
striations/mm on last whorl. Striations U-shaped and about as wide as deep
(Fig. 25), diminishing slightly near base. Interspaces between striations flat
and glossy. Aperture elongate-pyriform, about half as wide as high and
about 0.36-0.40 times length of shell (0.39 in holotype). Columella weakly
concave in outline; generally slightly twisted at base but may be evenly
arched in large specimens (Fig. 29). Parietal wall with a thin hyaline deposit
that is slightly thickened and granular over columella (Fig. 26).
Measurements in mm of seven paratypes and the holotype (in
parenthesis) are as follows: length 4.7-5.9 (4.68), width 1.6-1.8 (1.68),
aperture height 1.89-2.10 (1.82), and aperture width 1.0 (0.98).
TYPE LOCALITY.-- Mona Island, Sardinero (Station 3). Specimens
were collected along the base of a limestone bluff in leaf debris.
HOLOTYPE: UF 40831; collected 21 May 1974 by Fred G. Thompson.
Paratypes: UF 40832 (10), UF 40833 (SEM shell); same data as the
holotype.
DISTRIBUTION.-- Endemic to Mona Island. Other localities from
which it was collected are Stations 1, 8, and 12.
REMARKS.-- Varicella nesiotes is closely related to two species from
Hispaniola, V. verberata (Pilsbry) and V. una (Pilsbry). Both were described
as species of Sigmataxis, which then was regarded as a subgenus of Spiraxis
(Pilsbry 1907:43-44). Neither has been mentioned in the literature since it
was named. These three snails form a disparate group from other
Sigmataxis by having a tendency for the columella to be truncate and by
having a relatively enlarged body whorl. Other Sigmataxis, all of which are
Jamaican, have a strongly twisted columella and a proportionally smaller
body whorl. In these respects the Hispaniolan species and V nesiotes are
intermediate between Sigmnataxis and Varicella (s. gen. Varicellula), which is
also Jamaican. Their subgeneric relationships cannot be clarified until
anatomical material is examined.
V verberata is a more robust species than V. nesiotes and has a
proportionally larger, more inflated body whorl. In addition V. verberata
has a more conspicuously twisted columella, and the striations are nearly
obsolete below the periphery of the last whorl. V. una is a smaller species
than V nesiotes, being just over 4 mm long. Its striations are closer
(12/mm), and the columella is strongly twisted near the middle as opposed
to near the base as in V. nesiotes.
ETYMOLOGY.-- The specific name nesiotes is from the classical
Greek meaning insular.







THOMPSON: MONA ISLAND LAND SNAILS


BULIMULIDAE

Bulimulus guadalupensis (BRUGUIERE)

This species was recorded from Mona Island by Clench (1950:273)
as B. g. guadalupensis and as B. g. eyreisii (Drouet). Breure (1974:15-26, 46-
47) showed that eyriesii is a distinct species, and that the specimens
recorded from Mona Island are typical guadalupensis. I did not encounter
guadalupensis on Mona, even though I collected at the same stations from
where Clench recorded it. Apparently it is no longer extant on the island.
Breure (1974:51) suggested that the occurrence of this species outside of
the Windward Islands is attributable to human introductions.


Bulimulus d. diaphanus (PFEIFFER)

Found at Stations 1, 4, 5, 8, 11, and 12. It was most abundant on
the south coastal plain among clumps of grasses. It is generally present on
the plateau but is sparser in its occurrence there. Breure (1974:32)
recorded this species from Mona Island based upon specimens in the MCZ.


Drymaeus virgulatus beattyi CLENCH

Drymeaus elongatus beattyi Clench, 1950:273-274, figs. 4-6.
D. virgulatus (Ferussac) (=elongatus Bolten) is widespread on
Puerto Rico and its satellite islands, the Virgin Islands, St. Martin, St.
Eustatius, Curacao, Bonaire, and Aruba. Baker (1924:80-85) presented
evidence suggesting that the species was introduced through commerce to
the last five islands. Its wide distribution on Puerto Rico and the Virgin
Islands apparently is natural (Pilsbry, 1899:23-27). Drymaeus virgulatus is
highly variable in color and, to a lesser extent, in relative obesity. Several
names have been proposed for some of these variants, including liliaceus
Ferrusac (see Baker, 1962:120). D. v. beattyi is most similar in shape and
size to the fossil form extinctus (Pfeiffer) from St. Croix. It is least similar to
the larger, more obese forms occurring on Puerto Rico. It is distinguished
from all forms of virgulatus by having a narrow, elongate aperture that bears
a reflected basal lip. D. v. beattyi is common and nearly ubiquitous on Mona
Island. It was collected at all stations. There is considerable local variation
in size and obesity, and Mona populations overlap in these traits with
extinctus. Measurements of selected specimens of beattyi taken from four
lots to show maximum variation are given in Table 2.








BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


Table 2. Measurements in mm of selected specimens of Dtymaeus v. beattyi taken from four
population samples to show maximum variation in size and proportions.


Station: 4 6 10 12


N 44 41 21 6
Length 19.5-24.0 19.1-26.2 21.6-27.4 19.2-22.4
Width 8.3- 9.7 8.2-10.5 9.0-11.3 8.3- 9.2
Aperture H. 9.1-11.4 9.2-11.9 10.3-13.1 9.3-10.4
Aperture W. 5.1- 6.0 5.1- 6.4 5.3- 6.8 5.1- 5.7
Whorls 5.6- 6.3 5.6- 6.5 5.7- 6.8 5.8- 6.2
Width/Length 0.38-0.46 0.38-0.46 0.38-0.48 0.40-0.44
Ap. W/Ap. H 0.52-0.62 0.50-0.60 0.48-0.56 0.52-0.55
Ap. H/Length 0.42-0.51 0.43-0.53 0.43-0.51 0.46-0.51







THOMPSON: MONA ISLAND LAND SNAILS


UROCOPTIDAE

Brachypodella beattyi CLENCH

Brachypodella beattyi Clench 1950:275; fig. 3.
B. beattyi is generally distributed on Mona Island. It was found at
Stations 1, 3, 4, 11, and 12. This species was described as closely related to
B. pallida (Pfeiffer), a species found on Puerto Rico and the Virgin Islands
of St. Thomas, St. Johns, and Tortola (Pilsbry 1904:84-85). B. beattyi differs
from B. pallida in several respects, including thin solid ribs and finer,
sparser costulate sculpture on the embryonic whorls (Fig. 30). B. pallida has
thick hollow ribs and the sculpture on the embryonic whorl consists of
denser, heavier axial threads (Fig. 31). In these respects B. beattyi is more
similar to some forms of the B. dominicensis complex from Hispaniola than
it is to B. pallida.


Microceramus stenegrus new species

Microceramus guanicanus Baker, Clench 1950:275.
SHELL (Figs. 32, 34, 35).-- Elongate-conical, about 0.40-0.48 times
as wide as high. Spire slender, straight-sided, regularly increasing in
diameter to base. Imperforate. Color opaque white with sparse vertical
wavy brown bars that are broader and closer on upper whorls but are clearly
defined throughout length of spire. Axis solid with a very weakly twisted
callus. Whorls 8.3-10.5 in specimens with expanded peristome; 2.0
embryonic whorls. Suture deeply impressed. Whorls angular at periphery,
particularly on upper spire. Body whorl with weak basal-lateral spiral ridge.
First half embryonic whorl smooth. Subsequent embryonic whorls
sculptured with uniform, thin, regularly spaced, vertical thread-riblets.
Postembryonic whorl sculptured with heavier oblique ribs that are slightly
recurved near the upper ends and frequently broken and irregular in
thickness, more so on lower whorls than upper. Ribs slightly thickened at
base, not crenulating suture. About 42-55 ribs on penultimate







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


32/ 33
Imm
FIGURES 30-33.- Fig. 30: Brachypodella beatti Clench, (UF 40870); sculpture of
apical whorls. FIG. 31: Brachypodella 2allida (Pfeiffer), (UF 40878), sculpture of apical
whorls. FIG. 32: Microceramus stenegrus new species. Paratype (UF 40830). FIG. 33:
Microceramus guanicanus Baker, (UF 40876, 10 km SE Guanica, Puerto Rico).







THOMPSON: MONA ISLAND LAND SNAILS


whorl in larger specimens (55 in holotype). Ribs continuous, but
diminished on base of last whorl. Aperture sub-rhomboid; slightly wider
than high, about 0.20-0.27 times height of shell; lying at an angle of about
400-48 to shell axis (430 in holotype). Peristome nearly uniformly
expanded and moderately thickened, incomplete across parietal wall.
Columella slightly oblique to shell axis.
Measurements in mm of holotype: length 6.85, width 2.80, aperture
height 1.54, whorls 10.1. Measurements of specimens from four population
samples selected to show population variation are given in Table 3.
TYPE LOCALITY.--Mona Island, Sardinero; at base of limestone cliff
in mesic forest (Station 1). HOLOTYPE: UF 40828; collected 12
November 1978 by Fred G. Thompson. PARATYPES: UF 40829(18),
same locality as holotype; UF 40830(91), Station 3.
DISTRIBUTION.-- This snail is generally distributed over the island
in mesic and submesic microhabitats. It was collected at Stations 1, 4, 8, 9,
11, 12, and 13.
REMARKS.-- Microceramus stenegrus is a member of a small group
of southern Caribbean species that also includes M. bonairensis (Smith) and
M. guanicanus Baker by virture of having ribs that do not crenulate the
suture and by being imperforate. M. bonairensis is confined to the Dutch
Leeward Islands and includes three subspecies that differ principally in size
(Baker 1924:95-98). M. guanicanus is known only from a small xeric
limestone peninsula east of Guanica, Puerto Rico. M. stenegrus is most
similar to M. guanicanus in size and sculpture. It differs from M. guanicanus
by having a slender, attenuate spire that is uniformly conical in large
specimens, whorls that are angular at the periphery, a more deeply
impressed suture, generally a weak baso-lateral ridge on the last whorl, ribs
that are much heavier and closer, and a more sharply defined color pattern
throughout the length of the shell. M. guanicanus (Figs. 33, 36, see also van
der Schalie, 1948: pl. 7, fig. 4) has a relatively obese spire that becomes
turrete in larger specimens, the whorls are rounded with a shallow suture,
the last whorl lacks a baso-lateral ridge, the ribs are narrower, lower, and
more widely spaced, and the color pattern is distinct only on the upper
spire. M. stenegnis is a more slender species than M. guanicanus. Both
species show considerable variations in the size of the body whorl and the
reflection of the peristome. Measurements of major diameter and total
length incorporate both of these variables, and on the basis of overall size
the two species overlap (Table 3). Measurements of the minor diameter








92 BULL FLORIDA STATE MUS., BIOL. SCI. 31(2)







Table 3. Measurements in mm of specimens from samples of Microceramus selected to show
variations in size.


M. stenegnis n. sp. M. guanicanus Baker


Station: 3 11 12 13 UF 40876 UF 40877


N 35 14 10 9 28 17
Major D. 2.0-2.5 2.0-2.4 2.3-2.7 2.3-2.6 2.5- 3.1 2.7- 3.0
Length 4.3-6.4 4.3-5.4 5.0-6.1 5.6-6.4 5.1- 7.3 5.7- 7.2
Maj. D./Length 0.38-0.47 0.41-0.51 0.39-0.48 0.39-0.44 0.40-0.51 0.39-0.47
Whorls 8.3-9.8 7.9-8.9 8.4-9.2 9.0-9.5 8.3-10.0 8.8-10.3
Aper. H 1.1-1.5 1.1-1.3 1.3-1.5 1.2-1.6 1.3- 2.0 1.4- 2.2
Aper.H./Length 0.21-0.27 0.23-0.28 0.22-0.26 0.21-0.27 0.23-0.29 0.23-0.27
Minor D. 1.8-2.2 1.8-2.1 2.1-2.4 2.1-2.3 2.2- 2.8 2.2- 3.0
Spire 3.3-5.0 2.7-4.3 3.7-5.9 4.4-5.1 3.6- 5.5 3.6- 6.1
Min. D./Spire 0.44-0.55 0.50-0.64 0.39-0.60 0.42-0.49 0.50-0.65 0.49-0.67







THOMPSON: MONA ISLAND LAND SNAILS


35 r
3mm


FIGURES 34-36.- FIGS. 34-35: Microceramus stenegrus new species (Fig. 34, Holotype
[UF 40828]; Fig. 35, Paratype [UF 40830]). FIG. 36: Microceramus guanicanus Baker (UF
40876).







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


and the length of the spire include less variable parameters, and significant
differences between the two species occur in the minor diameter and its
ratio to the length of the spire. Most M. stenegrus have a minor diameter of
1.8-2.2 mm and a minor diameter/spire ratio of 0.39-0.52 mm, whereas most
M. guanicanus have a minor diameter of 2.3-3.0 mm and a minor
diameter/spire ratio of 0.52-0.67 mm. These two differences apply to about
90% of the specimens examined.
Specimens of M. guanicanus examined for comparison. PUERTO
RICO: 7 km SE Guanica (UF 40877, 27 specimens); 10 km SE Guanica
(UF 40876, 38 specimens).
ETYMOLOGY.-- stenegrus, from the Classical Greek stenegros
meaning narrow, tight, alludes to the slender, compactly coiled spire.


SAGDIDAE

Hojeda inaguensis (WEINLAND)
(Figures 37-42)

Collected at Stations 1, 3, 8, 9, 11, 12, and 13 in leaf litter. This
snail is widely distributed on the Florida Keys, the Bahama Islands,
Hispaniola, and Mona Island. The use of the name inaguensis by Clench
(1950:272) for the Mona Island and Hispaniolan populations is supported
by anatomical data. I dissected preserved specimens from Station 12 (UF
40839). The reproductive anatomy essentially is identical to that of
specimens from Stock Island, Florida, described by Baker (1940:60).
Pilsbry (1940:984, Figs. 571) illustrates a specimen from Boca Chica
Key, Florida, as typical for the species. The specimen has an umbilical
opening that is about 1/4 (0.25) the width of the shell. I have examined
many series of specimens from throughout the range of the species, and
none approaches this condition. The umbilicus generally is much narrower,
being about 0.15-0.19 times the width of the shell. The snail is conservative
in its geographic variation, and the illustrations given in this paper (Figs. 37-
42) are representative for the species throughout its range. The sculpture
and protoconch characteristics are illustrated in Figures 43-45.
Measurements in mm of five specimens from Station 11 on Mona
Island are given for comparisons with the following species.





THOMPSON: MONA ISLAND LAND SNAILS


39
3mm


42
3mm


FIGURES 37-42.- Hoieda inag s (Weinland) (UF ). FIGS. 37-39: (UF 40844).
FIGS. 40-42: (UF 41575).


P







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


height width apert.h. apert.w. umbil.w. whorls
2.05 3.16 1.24 1.43 0.50 3.9
2.02 3.29 1.30 1.55 0.50 4.0
2.17 3.39 1.24 1.49 0.62 4.0
2.42 3.53 1.30 1.67 0.62 4.2
2.54 3.60 1.24 1.74 0.62 4.2



Hojeda insularis insularis new species

Hojeda inaguensis (Weinland) Thompson 1976; 152.
SHELL (Figs. 55-57).-- Small, about 3.4-3.7 mm wide. Depressed-
turbiniform, 0.57-0.64 times as high as wide. Spire low and broadly conical,
not depressed, dome-shaped as in H. inaguensis (Fig. 55). Umbilicus
moderately wide, about 0.23-0.28 times width of shell. Shell relatively thick
compared to other Hojeda, opaque, milky-white. Whorls about 4.0-4.1 in
mature specimens. Suture deeply impressed. Protoconch (Figs. 49-51)
about 1.4-1.5 whorls with numerous very fine spiral threads below periphery
as in H. inaguensis (Figs. 43-45); last 1/4 whorl of protoconch with fine
radial growth striations. Following whorls rounded; relatively narrow
compared to H. inaguensis (Figs. 37-40); sculptured with numerous
incremental growth striations that are irregular in intensity, becoming
slightly rough near peristome. Sculpture more rugose than in H. inaguensis
(Fig. 43) and nearly uniform over surface of whorls. Aperture semi-lunar in
shape, 0.75-0.88 times as wide as high, height 0.57-0.67 times height of shell,
width 0.44-0.47 times width of shell. Peristome slightly thickened with an
internal callus and blunt-edged at maturity. Columellar lip weakly reflected.
Parietal callus conspicuously thickened at maturity (Fig. 55) in contrast to
other species of Hojeda.
Measurements in mm converted from micrometer units of five
specimens selected to show variation are as follows:








THOMPSON: MONA ISLAND LAND SNAILS


FIGURES 43-48.- FIGS. 43-45: Hojeda inaguensis (Weinland); UF 40777. Fig. 43, X
15; Fig. 44, X 50; Fig. 45, X 150. FIGS. 46-48: Lacteoluna selenina (Gould); UF 40820
(Stock Island, Monroe Co., Florida). Fig. 46, X 15; Fig.47, X 30; Fig.48, X 150.







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


49 52


























FIGURES 49-54.- FIGS. 49-51: Hoieda i. insularis new species, Paratype (UF 40779).
Fig. 49, X 20; Fig. 50, X 53; Fig. 51, X 159. FIGS. 52-54: Hoieda insularis eurytrema new
subspecies, Paratype (UF 40778). Fig. 52, X 20; Fig. 53, X 53; Fig. 54, X 159.







THOMPSON: MONA ISLAND LAND SNAILS


height width apert.h. apert.w. umbil.w. whorls
Holotype 2.29 3.60 1.30 1.67 0.87 4.1
Paratype 2.05 3.41 1.18 1.59 0.87 4.0
Paratype 2.05 3.60 1.30 1.61 0.93 4.0
Paratype 2.17 3.53 1.24 1.55 0.93 4.0
Paratype 2.23 3.72 1.30 1.74 0.99 4.1

TYPE LOCALITY.--Monito Island (1809'30"N, 67057'15"W).
HOLOTYPE: UF 40814; collected 20 May 1974 by Fred G. Thompson.
PARATYPES: UF 40815 (76), UF 40779 (1 SEM shell), UF 40821 (2
SEM shells); same data as holotype.
REMARKS.-- Hojeda includes four other species: H. inaguensis
(Weinland) is widely distributed from the Florida Keys, through the
Bahama Islands, Hispaniola, and Mona Island; H. vanattai Baker (1924) is
endemic to Aruba; H. boothiana (Pfeiffer) is a large species (5 mm wide)
that occurs in Cuba; H. micromphala Pilsbry is widely distributed on
Hispaniola. H. insularis differs from all by the same characteristics in which
it differs from H. inaguensis.
In general appearance, the shell of H. i. insularis suggests a
relationship to Lacteoluna, which also has spiral sculpture on the
protoconch (Figs. 46-48). However, the spiral sculpture in Lacteoluna is
coarser, and it occurs over the entire surface of the protoconch. In Hojeda
it is confined to the periphery. Moreover, all the species placed in
Lacteoluna (s.s.) by Baker (1935a:52) have discoidal shells with a bluntly
angular periphery.
The discoidal form of the following subspecies approaches that of
Lacteoluna. The generic relationships of these two new taxa remain
tentative until their reproductive anatomies are examined; nevertheless,
their protoconch sculpture strongly indicates congeneric relationships with
Hojeda.


Hojeda insularis eurytrema new subspecies

SHELL (Figs. 58-60).-- Similar to H. i. insularis in most aspects of
color, sculpture, and protoconch characteristics (Figs. 52-54). It differs by
having a thinner, transparent shell. The spire is more depressed, with the
shell being about 0.53-0.57 times as high as wide. The umbilical perforation
is relatively broader, being about 0.26-0.30 times the width of the shell. The
parietal callus is very thin and is nearly indistinguishable.






BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


-jI~


60
3mm


FIGURES 55-60.- FIGS. 55-57: Hojeda i. insularis new species, Holotype (UF 40814).
FIGS. 58-60: Hoieda insularis eurvtrema new subspecies, Holotype (UF 40816).


Ilh







THOMPSON: MONA ISLAND LAND SNAILS


Measurements in mm converted from micrometer units based on
the five largest specimens available from the type locality follow:

height width apert. h. apert. w. umbil. w. whorls
Holotype 1.74 3.16 1.05 1.30 0.87 3.9
Paratype 1.55 2.91 0.88 1.24 0.81 3.7
Paratype 1.55 2.91 0.93 1.30 0.87 3.7
Paratype 1.61 2.98 0.99 1.24 0.87 3.8
Paratype 1.80 3.35 0.93 4.2

TYPE LOCALITY.-- The base of limestone cliffs at Playa Pajaros,
Mona Island (Station 9). HOLOTYPE: UF 40816; collected 23 May 1974
by Fred G. Thompson. PARATYPES: UF 40817 (5), UF 40778 (1 SEM
shell), same data as holotype; UF 40819 (6), Coral de Los Indios (Station
11). All specimens are dead shells recovered from leaf litter.
REMARKS.-- H. i. eurytrema differs from H. i. insularis to an extent
that would constitute specific distinctions among most members of this
family. Nonetheless the two taxa are very similar in appearance and
apparently are closely related. The two samples from Mona Island consist
of only a few specimens and most of these appear to be immature.
ETYMOLOGY.-- The name eurytrema is from the Classical Greek
eurys, meaning wide, and trema, a hole, and alludes to the wide umbilical
perforation of this taxon.


POLYGYRIDAE

Thysanophora plagioptycha (SHUTTLEWORTH)

A single shell was recovered from leaf litter in a patch of mesic
forest at Station 11.


XANTHONYCHIDAE

Hemitrochus gallapavonis (PFEIFFER)

Found at Stations 2, 4, 5, and 6. This snail occurs in the Turks and
Caicos Islands. It has been found on Mona Island only on the south coastal
plains, the portion of the island that was homesteaded. It probably was
introduced, as discussed by Clench (1950:250).







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


Plagioptypcha musicola fortisculpta new subspecies

Plagioptycha euclasta (Shuttleworth), Clench 1950:276.
SHELL (Figs. 61-65).-- Depressed-helicoid with a low dome-shaped
apex. Shell 0.51-0.66 times as high as wide. Brown, opaque; aperture,
peristome, and columella lighter brown or dusky. Suture weakly impressed.
Umbilicate; perforation half covered by columellar reflection. Whorls 4.6-
4.7 in larger specimens. Embryonic whorls 1.8. Upper whorls weakly arched
between sutures. Body whorl bluntly angulate at periphery and descending
slightly to the aperture. Peripheral angle of last whorl lying below middle of
whorl. Body whorl strongly curved below periphery, moderately arched
above. First 1.2 embryonic whorls smooth. Subsequent whorls with strong,
oblique, recurved axial ribs that are continuous across the surface of the
whorls and into the umbilicus where they are only slightly diminished in
size. Interspaces about 2-3 times as wide as ribs. Ribs smooth and glossy,
interspaces sculptured with a meshwork of extremely fine granules.
Aperture semi-elliptical, about 0.58-0.63 times as high as wide. Peristome
incomplete across parietal wall; simple, not reflected or thickened internally.
Parietal wall with a thin but well defined parietal callus. Columella nearly
vertical and widely reflected above, continuing obliquely into basal lip.
Measurements in mm of the holotype and three paratypes selected
to show maximum variation follow:

height width apert. h. apert. w. whorls
Holotype 6.1 9.8 3.7 5.6 4.7
UF 40825 5.2 10.0 3.2 5.5 4.6
UF 24979 6.8 10.3 3.8 6.3 4.7
UF 40826 6.7 11.3 3.7 6.3 4.7

TYPE LOCALITY.-- Mona Island, Bajura de Las Cerezas (Station
12). HOLOTYPE: UF 40823, collected 13 November 1978 by Fred G.
Thompson. Paratypes: UF 24979 (3), same data as holotype; UF 40825 (3),
Coral de Los Indios (Station 11); UF 40824 (1), Lirio Lighthouse (Station
10); UF 40826 (1), 1 km W Uvero (Station 7); MCZ 171028 (2), "Mona
Island." Apparently this snail is arboreal. Fresh dead shells and one live
juvenile were found in bromeliads.
REMARKS.-- P. m. fortisculpta is closely related to P. m. musicola
(Shuttleworth), from which it differs by the shape of the shell, the







THOMPSON: MONA ISLAND LAND SNAILS


67 68 69







70 71 72




FIGURES 61-72.- FIGS. 61-65: Plagioptycha musicola fortisculpta new subspecies.
FIGS. 61-63: Holotype (UF 40823). FIG. 64: Paratype (UF 24979). FIG. 65: Paratype
(UF 40826). FIGS. 66-69: Plagioptycha musicola euclasta (Shuttleworth). FIG. 66: ANSP
28305; St. Thomas Island, Virgin Islands. FIGS. 67-69: ANSP 1032; St. Thomas Island,
Virgin Islands. FIGS. 70-72: Plagioptycha m. musicola (Shuttleworth). ANSP 256407;
Cabo Rojo, Mayaguez Dist., Puerto Rico. All figures X 5.5.







BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


shape of the aperture, by having more whorls, and by having a shallower
suture. P. m. fortisculpta (Figs. 61, 64, 65) has a depressed dome-shaped
spire, and the peripheral angle lies below the middle of the last whorl. The
aperture is narrowly elliptical. In mature specimens the shell consists of
about 4.6-4.7 whorls that are separated by a shallow suture, which results in
relatively flattened whorls between the suture. P. m. musicola (Fig. 70) has
a helicoid or depressed helicoid spire and the periphery of the last whorl lies
at or above the middle of the whorl. The aperture is more broadly elliptic.
Seldom does the shell have more than 4.2 whorls, with a maximum of 4.4
whorls (33 lots examined; ANSP, UF), and the suture is deeply impressed,
producing strongly arched whorls between the sutures. P. m. fortisculpta
generally bears stronger sculpture than does P. m. musicola. All P. m.
fortisculpta examined are rugosely costate. Generally, P. m. musicohl is
more weakly sculptured, but this trait is highly variable. In a single lot some
specimens may be nearly smooth, while others may be quite strongly costate.
The two subspecies also differ in the development of the parietal callus. P.
m. fortisculpta has a distinct but thin callus. P. m. musicola has a thinner.
hardly noticeable parietal deposit.
P. m. fortisculpta was previously reported from Mona Island as
Plagioptycha cuclasta (Shuttleworth) (Clench 1950:276). Some observations
regarding the systematics of P. musicola (Shuttleworth 1854) are
appropriate at this point. P. musicola was originally described as a Helic
(Helicidae), as were most other helicoid snails at that time. Pilshry
(1894:57) placed musicola in Thysanophora (Polygyridae), where he
included an heterogenous assortment of unrelated species. Later, Pilsbry
(1926:112) proposed the genus Suavitus (Sagdidae) and the subgenus
Euclastaria and designated musicola as the type species of the latter. Baker
(1943:85) showed that anatomically Euclastaria is in the Xanthonychidae.
subgenerically related to Plagioptycha.
P. musicola is divided into three subspecies in addition to P. im.
fortisculpta: P. m. musicola (Shuttleworth), P. m. euclasta (Shuttleworth).
and P. m. bcattyi Clench. P. m. musicola (Figs. 70-72) is widely distributed
in Puerto Rico and is typical of wetter and more elevated localities. P. in.
euclasta (Figs. 66-69) is found along lower, drier coastal areas of Puerto
Rico, St. Thomas, St. Johns, Tortola, and Vieque (Baker 1961:145). Ic\\
differences occur between the two subspecies. P m. cclasta is more
depressed than P. m. musicola. Great overlap occurs in this character in
some population samples from Puerto Rico and the Virgin Islands (van der
Schalie 1948:83-84). Clench (1950:276) apparently overlooked \a;n de
Schalie's observations and continued to treat eclc/asta as a difrncit .prLcies.
Baker (1961:145) reaffirmed van der Schalie's observations. l'he third
subspecies, P. m. beattyi, is known only from St. Croix (Clench 1040(:244). It
is characterized by having a depressed shell with an acutrelv c;rini;atc
periphery.








THOMPSON: MONA ISLAND LAND SNAILS


ETYMOLOGY.-- The name fortisculpta is from the Latin fortis,
meaning strong, and sculpta, carved, and alludes to the strong sculpture of
this subspecies compared to other subspecies of Plagioptycha musicola.



LITERATURE CITED



Aaron, J.M. 1975. Geology and mineral resources of Isla de Mona P.R. Appendix B in
F.H. Wadsworth (ed.). Las Islas de Mona y Monito: Un Evaluaci6n de sus
Recursos Naturales e Hist6ricos. Vols. I, II. Estado Libre Asociado de Puerto
Rico, Oficina del Gobernador, Junta de Calidad Ambiental.
Adams, C.B. 1849-52. Contributions to Conchology. Bailliere, New York, 258 pp.
Baker H.B. 1924. Land and freshwater molluscs of the Dutch Leeward Islands. Occ. Pap.
Mus. Zool. Univ. Michigan (152):1-159; pls. 1-21.
1928. Mexican mollusks collected for Dr. Bryant Walker in 1926. Pt. I. Occ.
Pap. Mus. Zool. Univ. Michigan (193):1-65; pls. 1-6.
1934. Jamaican land snails. Nautilus 48:6-14.
S1935. Jamaican land snails, 2. Nautilus 48:84-88.
1935a. Jamaican land snails, 6. Nautilus 49:52-58.
1940. Some Antillean Sagdidae and Polygyridae. Nautilus 54:54-62; pls. 4, 5.
1941. New Puerto Rican land snails. Notulae Naturae (88):1-6.
1943. Some Antillean helicids. Nautilus 56:81-91; pls. 9-11.
1961. Puerto Rican Xanthonichidae. Nautilus 74:142-149.
1962. Puerto Rican Holopopodes. Nautilus 75:116-121.
1962a. Puerto Rican land operculates. Nautilus 76:16-22.
Breure, A.S.H. 1974. Caribbean land molluscs: Bulimulidae, 1; Bulimnulus. Stud. Fauna
Curacao and other Caribbean Islands 45:1-80; pls. 1-8.
Clench. W. J. 1940. Two new land shells from Puerto Rico and St. Croix. Mem. Soc.
Cubana Hist. Nat. 14:243-244; pl. 42.
1950. Land shells of Mona Island, Puerto Rico. .. Conchyl. 90:269-276.
Dall, W. H., and C.T. Simpson. 1901. The Mollusca of Puerto Rico. Bull. U.S. Fish. Comm.
(1900) 1:352-524; pls. 53-58.
Pfciffer, L. 1849. Description of twenty-nine new species of Helicina, from the collection ol
H. Cuming, Esq. Proc. Zool. Soc. London for 1848:119-125.
Pilsbry. H.A. 1894. Manual of Conchology, Ser. II, 9:i-xlviii, 1-366. pls. 1-71. Philadclphia.
1899. Manual of Conchology, Ser. II, 12; 1-258; pls. 1-64. Philadclphia.
1903-1904. Manual of Conchology, Ser. II, 16:i-xi, 1-329; pls. 1-37. Philadclphia.
S 1907-1908. Manual of Conchology, Scr. 11, 19:i-xxvii, 1-333, Ils. 1-52.
Philadelphia.
1926. The land mollusks of the Republic of Pl'aniu:ma and the Canal /t.I I'lno.
Acad. Nat. Sci. Philadelphia 78:57-133.
1940. Land Mollusca of North America, Vol. I, Plt. 2. Monoglr. -\ciad. Nit. Sc!
Philadelphia: 575-994.








106 BULL. FLORIDA STATE MUS., BIOL. SCI. 31(2)


Schalie, H. van der. 1948. The land and freshwater mollusks of Puerto Rico. Misc. Publ.
Mus. Zool. Univ. Michigan (70):1-133; pls. 1-14.
Shuttleworth, R.J. 1854. Diagnosen Neuer Mollusken, No. 6. Beitrage zur naheren
Kenntnis der Land- und Sisswasser-Mollusken der Insel Portorico. Bern. Mitth.
Natur. Gesel.: 33-56.
Thompson, F.G. 1976. Land snails from Monito Island, West Indies. Nautilus 90:152-153.
1982. The Helicina umbonata complex in the West Indies (Gastropoda,
Prosobranchia, Helicinidae). Bull. Florida State Mus., Biol. Sci. 28(1):1-23.
Wadsworth, F.H. 1975. The historical resources of Mona Island. Appendix N in F.H.
Wadsworth (ed.). Las Islas de Mona y Monito: Un Evaluaci6n de sus Recursos
Naturales e Hist6ricos. Vols. I, II. Estado Libre Asociado de Puerto Rico,
Oficina del Gobernador, Junta de Calidad Ambiental.
Woodbury, R.O. 1975. The vegetation of Mona Island. Appendix G in F.H. Wadsworth
(ed.). Las Islas de Mona y Monito: Un Evaluaci6n de sus Recursos Naturales e
Hist6ricos. Vols. I, II. Estado Libre Asociado de Puerto Rico, Oficina del
Gobernador, Junta de Calidad Ambiental.









Contributions to the BULLETIN OF THE FLORIDA STATE MUSEUM,
BIOLOGICAL SCIENCES SERIES, may be in any field of biology. Manuscripts dealing with
natural history of systematic problems involving the southeastern United States or the New World
tropics are solicited especially. Manuscripts should be of medium length--circa 35 to 200 pages
(10,500-60,000 words). Examination for suitability is made by an Editorial Board.
The BULLETIN is distributed worldwide through institutional subscriptions
and exchanges. It is considered the responsibility of the author to distribute his paper to all inter-
ested individuals. To aid in this the authors) receives) 50 copies free, and he(they) may purchase
additional separates at cost if ordered when page proof is returned. The author is also responsible
for any charges incurred for alterations made by him on galley or page proofs. The Museum will
send an invoice to the author for this amount upon completion of publication.

PREPARATION OF MANUSCRIPT

Contributors should consult recent numbers of the BULLETIN for preferred
style and format. Highly recommended as a guide is the CBE Style Manual, 3rd Edition, 1972
(American Institute of Biological Sciences, Washington, D.C.).
Manuscripts must be submitted in duplicate and satisfy the following minimal
requirements. Please submit duplicate copies of manuscripts. They must be double-spaced
throughout, including tables, figure captions, and literature citations. Figure legends and tables
should be typed on separate sheets. Also, please submit a copy of the complete text and tables on
one or more 51/4" flexible diskettes from (1) IBM or compatible microcomputer with Microsoft
WORD; or (2) Apple microcomputer with Applewriter submit document files. If that is not
possible, the editors will have such diskettes prepared commercially at author's expense upon ac-
ceptance of the manuscript.
All illustrations are referred to as figures. They must comply with the following
standards: Photographs should be sharp, with good contrast, and printed on glossy paper. If the
background of photographs (especially those of specimens) is not desired, amberlith should be cut
out and used to cover the background. Drawings should be made with dense black waterproof ink
on quality paper or illustration board. All illustrations should have a cover sheet. All lettering will
be medium weight, sans-serif type (e.g. Futura Medium, News Gothic) in cutout, dry transfer, or let-
tering guide letters. Make allowance so that after reduction no lower case letter will be less than 1
mm high (2 mm is preferred) nor any capital letter greater than 5 mm high. The maximum size for
illustrations is 9" x 14" (twice BULLETIN typepage size); illustrations should not be less than type-
page width (41/2"). With soft lead pencil on the back of each illustration, designate the top and iden-
tify each by author's name, manuscript title, and figure number.
All manuscripts not submitted in BULLETIN format will be returned to the
author for retyping.

Manuscripts and all editorial matters should be addressed to:

Managing Editor of the BULLETIN
Florida State Museum
University of Florida
Gainesville FL 32611
U.S.A.







University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs