George Washington Tryon.

Manual of conchology; structural and systematic. With illustrations of the species. Second series: Pulmonata (Volume 2) online

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Online LibraryGeorge Washington TryonManual of conchology; structural and systematic. With illustrations of the species. Second series: Pulmonata (Volume 2) → online text (page 1 of 20)
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Animal protected by a spiral, heliciform shell, within which
it is completely retractile ; tail provided with a caudal mucus-
pore ; jaw with a median inferior projection, not ribbed ; the
central tooth in the lingual ribbon is tricuspid, with the middle
cusp long and narrow, laterals bicuspid, marginals acuminate,
unicuspidate or bicuspidate.

Shell usually heliciform and perforate or umbilicate, often
thin, and more or less transparent, the lip of the aperture sim-
ple, neither reflected nor with thickened margin.

The family thus defined includes several hundred species,
usually considered Helices, but which differ from that group in
the generally thinner, more translucent shells, the aperture with
simple margin ; the-genuine Helices being generally thicker, and
with the margin of the aperture either reflected or thickened within.

The jaw also is not ribbed, unlike most Helices, and the den-
tition differs. Externally, the animal is at once distinguished
from Helix by the presence of a mucus-pore. There are some
pulmoniferous mollusks having Zonitoid shells, whilst their soft
parts place them in Helicidae, and vice versa. The animals of
most of the species, however, are entirely unknown to science,
and we are thus reduced to analogies of the shell in determining
their systematic position. On the side of the Vitrinidae the re-
lations of both animal and shell are quite as intimate, the group
Otesia, for instance, which at the last moment I decided to in-
clude in the latter family, being made a member of the Zonitidse
by Pfeiffer, Fischer and other good authorities. The Yitrinid
mantle-lobes exist in a modified form in some of the groups of
the present family.


The want of sharply defined characters makes the division of
the family into generic and subordinate groups very unsatisfac-
tory, and authorities differ widely as to the systematic position
of many of the species. As most of these are known to us by
the shell only, whilst some of the groups are differentiated en-
tirely upon anatomical grounds, it is difficult to arrive at satis-
factory conclusions regarding them. In Pfeiffer's "Nomenclator
Heliceorum," many species are undoubtedly erroneously grouped,
but it is the only attempt recently made to arrange all the spe-
cies, and I believe that the best interests of science will be con-
served by adopting Pfeiffer as tin; basis of my classification,
correcting such errors as have been indicated, or are apparent to
me, and adopting such new groups us have been proposed by
more recent systematists, but usually without attempting their
enlargement l)y incorporating additional species with them.
When I shall depart from this rule it will be generally on account
of the geographical distribution of a newly proposed group indi-
cating pretty conclusively the common origin of its assigned
species, and those not heretofore referred to it, but partaking of
its features.

The monographer of the Zonitidye has ample material for
his work in Pfeiffer's several volumes, " Monographia Heliceorum
Viventium " and his " Nomenclator Heliceorum," in the beauti-
fully illustrated monograph of Reeve, " Conchologia Iconica,"
the Helicidse of Kiister's u Conchological Cabinet," Pfeiffer's
" Novitates ConchologicaV' Kossmassler's " Jeonogniphie," and
numerous other works and papers.

Synopsis of Genera.
Genus NANINA, Gray, 1834.

Shell dextral or sinistral, lieliciform, usually rather thin and
polished, the periphery rounded or angulated,columellar lip short,
reflected, often covering the umbilicus, outer lip simple, sharp.

Animal capable of complete retraction within its shell, the
mantle furnished with an anterior lobe often bilobate, and a
collar which is sometimes simple, and sometimes provided with
one or two lobules reflected upon the shell ; these mantle-lobes
possess some power of lateral movement and of expansion and
retraction. Foot long and narrow, subtruncate posteriorly and


glandular, the pore slit-like, often surmounted by M horn-shaped

Distribution. About six hundred species have been described,
many of which are simply varietal forms; they inhabit the
tropical regions of the old world, Africa, Asia and its islands,
Philippines, Polynesia, etc.

The Naninas are closely related to the genus Zonites, which
is largely American and European in distribution, although :i
few of its species occur in countries inhabited by the former.
They may be distinguished from Zonites by a generally larger,
less polished, thicker shell, and by the animal having cervical
mantle-lobes, and frequently polishing appendages, by their
genital orifice close to the tentacle, and by the marginal teeth of
the radula being bicuspidate.

Subgenus ARIOPHANTA, Desmoulins, 1833.

Shell sinistral, umbilicated, often angulated on the periphery.

Animal. Mantle without polishing lobes ; mucus-pore large,
without coniform protuberance. East Indies.

Subgenus CCELATURA, Pfeiffer, 1817.

Shell dextral, often spirally sculptured, umbilical region
excavated, imperforate, columellar lip straight, oblique.

Mucous pore without horn, mantle-lobes but slightly developed.

Is. of Mauritius and Bourbon.

Subgenus ROTULA, Albers, 1850.

Shell dextral, subperforate ; spire depressed conical, last
whorl carinated at the periphery ; columella very short, vertical.

Mucous pore with but a slight protuberance ; mantle without
polishing lobes, left cervical lobe usually bipartite.

Mauritius, India, East Indies.

Section PACHYSTYLA, Morch, 1852 (restricted).

Columella thickened and flattened.

Section STYLODONTA, Jan, 1832.

Imperforate, rather solid, periphery subangulated ; basal
margin of aperture somewhat thickened, columella short,
oblique, bearing a fold-like tooth.

Erepta, Albers, 1850, is a synonym.

Section CALDWELLIA, H. Adams, 1873.

Shell small, subtrochiform, fragile, translucent, with angular
periphery and simple aperture.

Subgenus RHYSOTA, Albers, 1850.

Shell dextral, often large and rather thick for the genus, not
transparent, base excavated around the umbilicus.

Mantle without shell lobes, left cervical lobe bipartite ; mucous
pore surmounted by a corniform protuberance.

East Indies, Philippines, Polynesia.

Section RHYSOTA (restricted).

Upper and lower surface of the shell similarly sculptured,
rugose, finely vermiculate or granular; periphery more or less

Section HEMIPLECTA, Albers, 1850.

Shell granular or striated above, smooth or polished below.

Section EUPLECTA, Semper, 1870.

Shell striated or ribbed above. Cervical lobes of the mantle
developed, the left one divided ; shell lojbes rudimentary ; mucous
pore with a short horn. Philippines.

Inozonites, Pfeiffer, 1883, may be placed here.

Section ROTULARIA, Morch, 1872.

Shell resembling Rotula. Mucous pore with a horn-shaped
protuberance. Nicobar Islands.

Section TROCHONANTNA, Mousson, 1809.

Shell thin, striated above, smooth below, spire conical, periphery
angulated. Polynesia.

Section MARTENSIA, Semper, 1870.

Shell conical, keeled, perforate, sculptured above, smooth
below. Right shell lobe wanting, left cervical lobe bipartite ;
mucous pore with a horn. East Africa.

I think it ver} r doubtful whether the several African groups
proposed by Semper, Martens, Pfeffer, etc., ought really to be
separated from Trochonanina. Ledoulxia, Bourg., 1885, might
as well be united with Martensia for the present ; it is founded
upon very unimportant characters of the shell alone, and takes
for its type the variety albopicta of N. Mozambicensis, the latter
the typo of Marlensia.


Section ZINGIS, Martens, 1878.

Shell heliciform with simple peristome ; last whorl with rounded

Animal without shell lobes, but with two cervical lobes, with
horn over the mucous pore ; jaw smooth. Zanzibar.

? Section HAMYA, Bourg., 1885.

Shell Hyalina-like, strangulated near the aperture, as in

N. REVOILI, Bourg. Quaternary. East Africa.

Section TROCHOZONITES, Pfeffer, 1883. West Africa.

Section SITALA, H. Adams, 1856.

Shell conoid, thin, whorls numerous, usually spirally ribbed
or striated ; base convex, narrowly or indistinctly umbilicated.

Animal long and narrow ; tail gland surmounted by a distinct
horn ; two shell lobes and two cervical lobes on the mantle, all
of them small and with no separately produced appendages ; jaw
thin, smooth, concentrically striated in the middle.

India, Burmah, East Indies.

Conulema, Stoliczka, 1871, is a synonym.

Section KALIELLA, Blanford, 1863.

Shell conical, with angulated periphery.

Animal with well-defined caudal appendage. India.

Subgenus ORPIELLA, Gray, 1855.

Shell thin, rounded, depressed, whorls convex, the last some-
what flattened basally.

Animal without shell lobes ; a protuberance over the mucous
pore, and several fleshy appendages in a double row along the

back of the tail.

Fiji Islands.
Subgenus XESTA, Albers, 1850.

Shell perforate, or narrowly umbilicate, orbicularly depressed,
smooth, usually polished ; aperture large, rounded ovate, margin
acute, columellar margin dilated and reflexed.

Animal with one or two shell lobes ; mucous pore simple, or
surmounted by a slightly developed corniform appendage.

Section XESTA (restricted). East Indies, India, etc.

Section XESTINA, Pfeffer. India.


Section MACROCHLAMYS, Benson, 1832.

Shell depressed globose, pellucid or corneous, smooth and

Mantle with two long tongue-shaped shell lobes ; left cervical
lobe divided into two diverging portions ; mucous pore with
conical appendage. India, etc.

Tanychlamys, Benson, 1834, and Orobia, Albers, 1860, are

Section MACROCERAS, Semper, 1870.

Conical appendage of the mucous pore very long. Philippines.

Section BENSONIA, Pfeiffer, 1855.

Shell thin, perforate, obliquely sculptured above, crossed by
impressed revolving lines. India.

Section SOPHINA, Benson, 1859.

Shell with a callous columella, angulated at the basal margin,
and with a more or less acute umbilical carina.

Foot long, obliquely truncate, with a large tail gland and
distinct horn-shaped appendage; mantle lobes as large as in
Helicarion. Burmah.

Section EURYPUS, Semper, 1870.

Shell with obscurely keeled periphery, umbilicus very narrow.
Foot with the back broad, not carinated. Fiji Islands.

Aulacopus, Pfeffer, is a synonym.

Section DURGELLA (Blanford), Stoliczka, 1871.

Shell thin or membranaceous, globose or globosely conoid,
polished, narrowly perforate, columellar margin not much

Dorsal lobes moderate, shell lobes very ample, triangular
when extended ; mucous pore well developed, with large over-
hanging lobe. India, Burmoh.

Section MICROCYSTIS, Beck, 1837.

Shell small, subperf orated, usualty slightly keeled, glabrous ;
aperture large, subvertical.

Mantle margin t with shell lobe on right side only ; left cervical
lobe bipartite. Polynesia.

Helicopsis, Beck, 1837, and ? riatycloster, Hasselt, are syno-

ZONITlT^fc. 9

Section MICROCYSTINA, Morch, 1872.

Shell small, polished, with a deep notch at the columellar

Animal like Microcystis. India.

Section SAGDINELLA, Morch, 1872. Nicobar Islands.

Section THAPSIA, Albers, 1860.

Shell orbicularly depressed, thin, pellucid, undulatety decus-
sated, narrowl}' perforated ; peristome acute, columellar margin
narrowly reflected. West Africa.

Section LAMPROCYSTIS, Pfeffer. India, Polynesia.

Section OXYTES, Pfeiffer, 1855.

Shell usually large, obliquely striate or plicate, depressed,
carinated, umbilicated ; peristome expanded, thin, columellar
margin thickened.

Animal with short somewhat thickened tentacles ; mucous
gland without marked appendage ; right cervical lobe triangular,
well developed, left lobe bipartite, anterior portion large, pos-
terior very small and giving off short processes ; left shell lobe
a narrow ribbon, reflected over the peristome, no right shell
lobe. India.

Subgenus SESSARA, Albers, 1860.

Shell imperforate, depressed orbicular, costulate-slriate above,
base smooth, excavated, periphery angulated ; aperture depressed,
wide, basal lip denticulated, columellar thickened.

Mantle lobes small, but as in Xesta. Burmah.

Subgenus GUILLAINIA, Bourguignat.

Shell thick, calcareous, strongly striate or costulate, globular,
bluish white, peristome simple, obtuse, interior dark chocolate-

Animal with a large profound mucous pore with horn-like
appendage. Dentition and jaw as in Hyalina.

The shell reminds one of the genus Leucocliroa. East Africa.

Genus ZONITES, Montfort, 1810.

Shell subdepressed, umbilicated, very thin, more or less trans-
parent ; aperture semilunar, usually without teeth ; lip thin,


Animal elongate, completely retractile within the shell, having
a caudal mucus- pore, more or less developed, but consisting
usually of a simple linear slit ; mantle lobes small, not reflected
on the shell ; genital orifice distant from the right tentacle ; jaw
with a well-marked median rostrum ; lateral teeth bicuspidate,
marginals sharp, narrowly unicuspidate.

Europe, Western Asia, America.

Subgenus /UNITES (typical).

Shell depressed orbicular, widely umbilicated, striated above,
smooth below, rather solid, whorls numerous (fi or 7), lip sharp,
with a slight parietal callus.

Labial palpi small ; caudal gland reduced to a simple slit.

Southern Europe, Asia Minor.

The synonyms are jEgopis, Fitzinger, 1833, Tragomma, Held,
1837, Helicodes, Dumas, 1847, Verticillus, Moquin-Tandon, 1855,
Archseozonites, Sandberger (fossil).

Subgenus HYALINIA, Ferussac, em. 1819.

Shell thin, vitreous, fragile, shining, unicolored, corneous;
last whorl not descending at the aperture ; peristome thin, sharp.

Mucus-pore shallow, hardly distinct, extremity of the tail
slightly sinused, skin bluish.

Northern Hemisphere, species numerous.

Section VITREA, Fitzinger, 1853.

Shell small, fragile, shining-, hyaline, smooth, convexly de-
pressed, perforate or imperforate, aperture liumtc.

Crystallus, Lowe, 1854, is a synonym.

Section POLITA, Held, 1837.

Shell depressed or subdiscoidal, unibilicate, smooth, shining, ,
pellucid, corneous, the base more or less milky opaque, aperture
obliquely lunate.

This is the typical group. Its synonyms are Oxychilus, Fitz.,
1833; Lucilla^'Lowe, 1854; Euhyalina, Albers, 1857; Aploxtoma,
Moq.-Tand., 1855.

Section ZONITOTDES, Lehmann, 1864.

The animal differs from the typical Hyalinia in possessing- n
dart, like the Helicida 1 ; the shell is \\ Polila.


Section NAUTILINUS, Mousson, 1872.
Shell nautiloid, involute.

Section CONULUS, Fitzinger, 1833.

Shell small, pellucid, corneous, globosely turbinated or conic,
thin, usually perforate, aperture lunar, oblique.

Trochiscus, Held, 1837, and Petasia, Beck, 1837, are synonyms.

Section CONULOPOLITA, Bottger, 1879.

Not umbilicated, base planate, excavated in the middle; shell
large, subttirbinate ; whorls 6J-7, very slowly increasing ; aper-
ture depressed, lunar. Caucasus.

Section DIERAMA, Pfeiffer, 1877.

Not described ; instituted for a single species, H. DIERAMA,
Pfr. Hab. unknown.

Subgenus PHACUSSA, Hutton, 1884.

Shell depressed ; periphery rounded ; whorls 5-6, gradually
increasing. Mantle included. Jaw with flat ribs. New Zealand.

Subgenus STENOPUS, Guilding, 1828.

Shell depressed or conical, perforated, thin, diaphanous, lip

Animal with a linear locomotive disk, separated from the
lateral parts by a groove on either side as in Vaginula ; caudal
gland with a retractile appendage.

Mexico, Venezuela, West Indies.

Is Guppya, Morch, 1867, and Habroconus, Crosse and Fischer,

Subgenus OMPHALINA, Rafinesque, 1819.

Shell widely umbilicated, depressed orbicular, striated above,
smooth and shining below, aperture large. Labial palpi large,
caudal pore well-marked.

Europe, United States, Mexico, Guatemala.

Section OMPHALINA (restricted). United States.

Section MORELETIA, Gray, 1855. Mexico, Guatemala.

Section ZONYALINA, Martens, 1865. Mexico.

Said to be distinguished from Moreletia by the want of the
outer cervical lobe of the mantle.

1 2

Section PATULOPSIS, Strebel, 1880.

Shell Patula-like, periphery angulated, upper surface finely
ribbed-striate, umbilicus open, perspective. Left cervical lobe
of the mantle divergently bipartite. Mexico.

Section ^EGOPINA, Kobelt, 1879. Europe.

Includes the larger European species and is scarcely distinct
from Omphalina. Retinella, Shuttl., is a synonym.

Section MESOMPIMX, Ratinesque, 1819.

Shell umbilicate or perforate, conical or conical-depressed, thin,
plicately striated, brownish horn-color, usually lighter colored
below ; whorls close ; aperture lunar ovate, lip sharp, subreflexed
on the columella. United States.

Barely distinguished from Omphalina by its closer whorls,
plicate striae, and more conical form.

Subgenus GASTRODONTA, Albers, 18f><).

Shell subperforate or narrowly umbilicated, orbicularly
depressed, light horn-color, sometimes glassy, with more
or less numerous wrinkle-like striae; whorls, 5-7; aperture
lunate, its interior with lamellar denticles, not reaching the
acute margin. United States.

Section GASTRODONTA (typical .

Denticles within the outer and basal walls of the aperture,
occurring at rest-periods of the growth and persistent.

Section YENTRIDENS, Binney and Bland, 1869.

Aperture with revolving series of pliciform teeth within the
base only.

Section HELICODISCUS, Morse, 1864.

Minute, planorboid, with spiral striae ; aperture lamellarly
toothed within the outer lip.

? Section ODONTOSAGDA, .Martens, 1800.

Shell whitish, depressed, thin, umbilicated ; whorls 6, the last
with convex base ; aperture lamellarly toothed. Haiti.

? Section PROSERPINULA, Albers, 1860.

Discoidal, hyaline, transparent, covered perforate ; whorls 4^.
planulate, the last with shining callus around the umbilical
region; aperture with a spiral lamella attaining the margin.




Subgenus STRTATURA, Morse, 1864.

Shell small, striate, thin, translucent, without teeth in the

Jaw almost smooth, with a median furrow and notch ; central
tooth of the radula very large. United States.

Distinguished chiefly by the jaw and dentition.

Section PSEUDOHYALINA, Morse, 1864.

Shell minute, subdiscoidal, slightly convex above, unicolored,
closely striate-ribbed, umbilicus moderate. N. America.

Chanomphalus, Strebel, 1880, is a synonym.

Section PYCNOGYRA, Strebel, 1880.

Shell many-whorled, depressed conical above, whorls narrow,
ribbed-striate, translucent ; umbilicus rather large, bordered by
an obtuse angle. Mexico.

Subgenus JANULUS, Lowe, 1852.

Shell umbilicated, depressed orbicular, costulately striate
above, rather smooth below; whorl 7-8^, closely revolving, the
last convex at the base ; aperture lunar, peristome simple, thin,
with a callous ring within. Madeira.

Jaw and radula typical.

Genus SELENITES, Fischer, 1879.

Shell depressed orbicular, widely perspectively umbilicated,
strongly striate above, last whorl obliquely depressed above,
depression becoming more marked at the aperture ; extremities
of the peristome approaching.

Animal having the jaw of Zonitidae, but the dentition of the
Testacellida?. United States.

On account of the jaw and dentition, Dr. Fischer has made
this group the type of a family Selenitidae, interposed between
Testaceilidae (having similar teeth, but no jaw), and Zonitidse
(having similar jaw, but different teeth).

Section HAPLOTREMA, Ancey, 1881.
Shell much smaller, peristome sharp.

Section MORCHIA, Albers, 1860.

Shell darker colored, striatulate. West Indies.


Genus CIIAROPA, Albers, 1860.

Shell umbilicated, depressed, ribbed, usually hairy ; periphery

Animal with caudal mucous gland. Jaw flat-ribbed. Mar-
ginal teeth of the radula broad, usually with many points.

New Zealand, Polynesia.

Hutton (Trans. N. Zeal. Inst., xvi, 200) has made this the
type of a family Charopidae, the animal having heliciform den-
tition, with a mucus-gland on the tail, as in Zonites.

Section CHAROPA (typical).

Section GERONTIA, Hutton, 1884.

Shell depressed, widely umbilicated, striated ; periphery
rounded ; whorls about five, slowly increasing ; aperture oblique.

Animal heliciform ; mantle rather posterior, included ; tail
acute, with a mucus-pore but no papilla ; jaw smooth or striated.

New Zealand.

Section PYRBHA, Hutton, 1884.

Shell subperforate, thin, translucent, of 4.^-5^ regularly in-
creasing whorls. Mantle subcentral, reflected over the peris-
tome of the shell with an even margin; tail truncate, with a.
large papilla and mucous gland. Jaw with flat ribs. Marginal
teeth broad, with several points. New Zealand.

Section PSYRA, Hutton, 1884.

Imperforate or narrowly umbilicated, ribbed, not hairy,
periphery rounded. Jaw and teeth as in Charopa.

New Zealand.

Section THERASIA, Hutton, 1884.

Subperforate or narrowly perforate, conoidal, depressed,
periphery subcarinated ; whorls smooth, striated or with mem-
branous plaits. Jaw with flat ribs. Marginal teeth broad,
usually with several points. New Zealand.

Section THALASSTA, Albers, 1860.

Shell narrowly or moderately perforate, conic orbicular, thin,
pellucid ; whorls five or six, smooth or with membranous plaits,
slowly increasing, the last round or with angulate or carinate
periphery ; umbilical region impressed ; peristome simple, acute,
columellar margin slightly retlexed. Jaw flat-ribbed. Marginal
teeth longer than broad, with one point very much longer than
the others. New Zealand, Australia, Polynesia.


Genus XANIXA, Gray, 1834.
Subgenus ARIOPHANTA, Desmoulins, 1833.
N. KADAPAENSIS, Nevill. PL 1, figs. 1, 2.

Shell perforate, solid, obliquely striate, cliestnut colored, white
zoned at the suture, periphery and base; whorls 5i, the last
descending anteriorly, base inflated ; aperture concolored, lip
obtuse, white, columellar margin a little reflected, almost cover-
ing the perforation. Diam. 37, alt. 27 mill.

Kadapa, India.

Long known under the name of Helix Nicobarica, Chemn., but
is not found at the Nicobar Is.

N. LAIDLAYANA, Benson. PL I, figs. 3, 4, 5.

Shell narrowly imperforate, thin, obliquely striate, decussated
by crowded spiral stria;, translucent, shining, whitish, with a
narrow chestnut zone at the suture, a wider band above the
periphery, and a narrow one below it, throat and lip chestnut
colored ; whorls 5. suture lightly impressed ; the last whorl angu-
lated at the periphery, slightly descending in front, con vex below,
columellar margin greatly narrowing the perforation. Diam. 27,
alt. 15 mill.


N. parietalis, Martens, is a synonym. Sometimes only the
sutural and a narrow peripheral band are. present.

N. THYREUS, Benson. PL 1, fig. 6.

Shell umbilicated, depressed, solid, bluish horn color, closely,
sharply striate above, with obsolete slight spiral stria? ; whorls
5, with sutures scarcely impressed ; body whorl carinated, below
the car ina obsoletely chestnut fasciated, not descending at the
aperture ; base shining, radiate^ striate ; interior purplish
brown, white zoned in the middle. Diam. 35, alt. 16 mill.

Southern India.

N. ryxsolemma, Gray, is a synonym.

N. CYSIS, Benson. PL 1, figs. 7, 8.

Shell umbilicated, rather solid, closely plicate striate, light
olivaceous horn-colored, under a deciduous epidermis ; whorls 5,
with impressed suture, the last whorl wider, tumid, slightly
descending in front ; periphery very obsoletely angulated ; aper-


ture subpt'Mi-ly, lip it little thickened, the extremities joined by
n thin parietal callus. Diam. 45, alt. 24 mill.

Nilgherry Mts., India.
N. ampullarioides, Reeve (fig. 8) is a synonym.

N. AURIS, Pfr. PL 1, figs. 9, 10.

Shell umbilicated, thin, closely obliquely striulate, yellowish

1 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

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