_doma_, house.) _Fam._ Mytilacea, Lam.--_Descr._ Transverse, elongated,
cylindrical, equivalve, with the extremities rounded, and the posterior
extremity rostrated; umbones not prominent, terminal; hinge straight,
destitute of teeth; ligament linear, most conspicuous within; muscular
impressions two.--_Obs._ The shells composing this genus differ from
Modiola, not only in the cylindrical form, but also in the circumstance
from which the generic name is derived, i. e. of their living in
stones. Thus, while the form and structure of the shell bring it near
the Mytili or Muscle shells, the habits of the animal cause it to
approach the Lithophagi, or rock-eating molluscs of Lamarck. L.
Dactylus (fig. 161,) is the Mytilus Lithophagus of ancient authors.
LITHOLEPAS. Bl. ([Greek: Lithos], _lithos_, stone, [Greek: lepas],
_lepas_, rock.) De Blainville's name for LITHOTRYA, Sow.
LITHOPHAGIDÆ. Lam. ([Greek: Lithos], _lithos_, stone; [Greek: Phagô],
_phago_, eat or gnaw.) A family of the Conchifera Dimyaria, Lam.
consisting of terebrating bivalves, gaping anteriorly, having no
accessary valves; and containing the genera Saxicava, Petricola,
Venerupis, to which are added other genera enumerated in explanation of
figures 91 to 97. Notwithstanding the numerous genera which have been
created, I think that the most convenient arrangement will be to reduce
them to two, thus--
1. PETRICOLA, with distinct cardinal teeth, including, Clothe,
Venerirupis and Coralliophaga. Fig. 91, 92, 97.
2. SAXICAVA, without teeth, including Biapholius, Hiatella,
Sphænia, Byssomya, and Thracia. Fig. 93 to 96.
LITHOTRYA. G. B. Sowerby. ([Greek: Lithos], _lithos_, stone; [Greek:
truo], _truo_, to bore through.) _Fam._ Pedunculated Cirripedes,
Lam.--_Descr._ Eight unequal valves, forming a laterally compressed
cone, the lower central valves being very minute; pedicle fleshy, scaly
at the upper extremity; fixed at the base in a patelliform shelly
support.--_Obs._ This genus derives its name from the power possessed
by the animal of making dwelling holes in stones or pieces of rock. The
remarkable shelly cups at the base of the pedicle is regarded as
analogous to the shelly base of the Balanus, so that this genus would
form an intermediate link between the Sessile and Pedunculated
Cirripedes of Lamarck. Fig. 39, L. dorsalis. West India Islands.
LITIOPA. Ranz. _Fam._ Turbinacea, Lam.--_Descr._ "Shell not very thick,
horny, with a slight epidermis, rather transparent, conical, with
whorls somewhat rounded; the last being larger than all the rest
together; with the apex pointed, longitudinally grooved; aperture oval,
larger anteriorly than posteriorly, with the lips disunited, the right
lip simple, separated from the left by a rather indistinct notch, or a
slight emargination in the contour. The left lip slightly reflected
backwards, so as to form a kind of salient margin with the anterior
extremity of the columella, which is united, rounded, arcuated and
slightly truncated at the anterior."--_Obs._ The Molluscous animals,
whose shells are thus described, are found in the Mediterranean, and
are remarkable for the power of suspending themselves from the sea-weed
on which they live, by a thread resembling a spider's web. The general
appearance of the shell presents a medium between Phasianella and
Littorina, but it is apparently destitute of an operculum.
LITTORINA. Fer. (_Littus_, the sea-shore.) _Fam._ Turbinacea,
Lam.--_Descr._ Turbinated, thick; spire acuminated, consisting of few
whorls, about one third of the axis in length; aperture entire, large,
rounded anteriorly; outer lip thickened within, acute; columella rather
flattened; operculum horny, spiral, with rapidly increasing
volutions.--_Obs._ The shells composing this genus are known from Turbo
and Phasianella by the horny operculum; and from Trochus, which has
also a horny operculum, by the small number of the whorls. The
Littorinæ, among which may be enumerated the common Periwinkle, are, as
the name implies, found on sea shores, feeding upon seaweed, in all
parts of the world. Fig. 363, _L. Vulgaris_.
LITUACEA. Bl. The second family of Polythalamacea. Bl. The shells are
described as chambered, symmetrical, convolute in part of their extent,
but constantly straight towards the termination. The genus Spirula,
which is admitted into this family, does not properly belong to it, any
more than to the Lituolæ of Lamarck, in which it is also placed. It
does not agree with the descriptions of either. This family partly
corresponds with the "Lituolées," Lam. and contains the genera Lituola,
Ichthyosarcolites, Spirula, Hamites and Ammonoceras.
LITUACEA. Lam. A family of the order Polythalamous Cephalopoda, Lam.
containing the genus Spirula, fig. 471.
LITUITUS. Montf. SPIROLINA, Lam. Microscopic.
LITUOLA. Lam. A genus of microscopic Foraminifera.
LITUOLÆ. Lam. The third family of Polythalamous Cephalopoda, Lam. the
shells of which are described as partially spiral, the last whorl
continuing in a straight line. The transverse septa which divide the
chambers, are in general pierced by a siphon which breaks itself off
before it reaches the succeeding septum. This family contains the
genera of microscopic Foraminifera Lituola and Spirolina. The genus
Spirula, also placed in this family, does not by any means agree with
Lamarck's definitions "the last whorl continuing in a straight line."
LITUUS. Humph. CYCLOSTOMA? Lam.
LIVID. (From _lividus_.) Of a pale, dull, blue colour. The adjective is
sometimes used as a specific name. _Ex._ Conus _lividus_, Sanguinolaria
_livida_.
LOBARIA. Schum. SANGUINOLARIA rosea, Lam. (fig. 98) and other similar
species.
LOBATE or LOBED. Divided into parts.
LOBATULA. Fleming. A genus composed of two very minute species of
chambered shells. Serpula lobata and S. concamerata, Mont. Test. Brit.
515.
LOMASTOMA. Rafinesque. An imperfectly defined genus, probably belonging
to the Limnacea.
LONGITUDINAL. Lengthwise. Longitudinal striæ, ribs, &c. are those which
radiate from the apex and follow the spiral direction of the whorls, in
spiral shells; and from the umbo to the ventral margin in bivalves. The
term "decourantes" is employed by French conchologists. The bands in
Achatina, fig. 286, are longitudinal or spiral.
LORIPEDES. Poli. A genus composed of species of LUCINA, Auct. in which
the lunules are not prominent.
LOTORIUM. Montf. A genus composed of species of TRITON, Auct. in which
the aperture is effuse. T. Lotorium, fig. 400.
LOTTIA. Gray. PATELLOIDA, Quoy and Gaimard.
LUCERNA. Humph. A generic name applied to some species of Helix
included in De Ferussac's sub-genus Helicogena.
LUCERNELLA. Sw. A genus of "Lucerninæ," Sw. thus described: "Teeth on
both sides of the aperture; surface regularly and distinctly striated.
Circumference convex."
LUCIDULA. Sw. A sub-genus of Lucerna, Humph. thus described: "Aperture
transverse, both lips much thickened and united; the outer with
marginal obsolete teeth at the base; umbilicus closed. Barbadensis,
_Lam._ No. 49. p. 78. Fêr. Moll. pl. 47, 2, 3, 4."
LUCINA. Brug. _Fam._ Nymphacea, Lam. Conchacea, Bl.--_Descr._
Equivalve, inequilateral, orbicular, lenticular, radiately striated;
hinge with, generally, two minute cardinal teeth, which are sometimes
nearly obsolete, and two lateral teeth, on each side of the umbo in one
valve, one in the other; ligament external, partly hidden by the
margins of the valves when closed. Muscular impressions two in each
valve, the anterior one produced into an elongated, ligulate band, the
posterior short and semi-rotund; impression of the mantle not
sinuated.--_Obs._ The shells of this genus resemble Amphidesma in
general form, but are distinguished by the external ligament, the
elongated muscular impression, and the want of a sinus in the palleal
impression. East and West Indies, and European shores. Fig. 104, L.
Tigerina.
LUNULATE. (_Luna_, the moon, dim.) Moon-shaped, having the form of a
crescent. Applied most frequently to muscular impressions. Semilunar is
sometimes used, perhaps with greater accuracy, to express the same
shape.
LUNULE. An impression on the anterior dorsal margin of some bivalve
shells. The similar impression on the posterior dorsal margin is called
the _escutcheon_.
LUPONIA. Gray. A genus composed of species of CYPRÆA, Auct. which are
described as having the anterior of the columellar lip crossed by
several irregular ridges, without any distinct marginal ones,
internally narrow, flat; the shell pear-shaped, smooth, or
cross-ribbed. _Ex._ C. Algoensis, Luponia Algoensis, Gray, fig. 447.
LUTRARIA. Auct. (_Lutum?_ mud.)--_Fam._ Mactracea, Lam.--_Descr._ Thin,
equivalve, inequilateral, transverse, oblong or ovate, gaping at both
extremities; hinge with one double and sometimes one single cardinal
tooth in each valve, and a triangular, oblique pit with a prominent
margin, containing the ligament; muscular impressions distant; palleal
impression having a large sinus.--_Obs._ This genus differs from Mactra
in the entire absence or indistinctness of lateral teeth. Fig. 77, L.
Papyracea. (Ligula, Leach.) Fig. 78. L. Solenoides. Sandy and muddy
shores.
LUTRICOLA. Bl. LUTRARIA. Lam. Fig. 77, 78.
LYCOPHRIS. Montf. A microscopic fossil described as resembling
NUMMULITES, but having a granulated surface.
LYMNADEA. Sw. A sub-genus of "Mysca," Turton, in the family of Nayades,
Lam. thus described: "Posterior hinge margin elevated and winged; the
valves connate; the surface smooth. L. alata. _Sw._ _Ex._ Conch. (fig.
48.) fragilis. _Sw._ Zool. Ill. compressa, _Lea._ Am. Tr. iii. pl. 12.
f. 22." Sw. p. 379.
LYMNEA. See LIMNEA.
LYMNEUS. Lam. See LIMNEANA.
LYONSIA. Turt. Inequivalve species of ANATINA, Auct. which have no
spoon-shaped cavity in the hinge, but an accessary piece. L. striata,
fig. 491, 2.
LYRODON. Goldf. TRIGONIA?
MACLURITES. Lesuour. Journ. des Scienc. Nat. Philad. t. 1. p. 312. pl.
13. fig. 2, 3.
MACOMA. Leach. VENUS tenuis, Bl. and similar species, described as
"Clothed with an epidermis; striated, compressed, oval; the summits not
very prominent; two bifid teeth upon the right valve and a single
undivided one upon the left."
MACRODITUS. Montf. LENTICULINA, Bl. A genus of microscopic
Foraminifera.
MACROSPIRA. Guild. A genus composed of HELIX octona, Auct. Macrospira
aperta, Guild.
MACROSTOMATA. Lam. ([Greek: Makros], _macros_, long; [Greek: stoma],
_stoma_, mouth.) A family belonging to the first section of the order
Trachelipoda, the shells belonging to which are described as haliotoid
or ear shaped, with a very large aperture, destitute of an operculum.
This family contains the following genera, which maybe thus
distinguished.
1. VELUTINA. Globose, with velvety epidermis. Fig. 337.
2. STOMATIA. Ear-shaped; pearly within; including STOMATELLA. Fig.
335, 336.
3. SIGARETUS. The same, not pearly; including _Cryptostoma_. Fig.
334.
4. CORIOCELLA. The same, thin, transparent.
5. HALIOTIS. The same, not thin, nor transparent; with holes;
including _Padollus_. Fig. 338, 339.
6. SCISSURELLA. Heliciform, with a slit near the aperture. Fig.
340.
7. PLEUROTOMARIA. Trochiform, with a slit at the edge of the
aperture. Fig. 341.
MACTRA. Auct. (_Mactra_, a kneading trough.) _Fam._ Mactracea, Lam.
Conchacea, Bl.--_Descr._ Usually thin, equivalve, sub-equilateral,
sub-trigonal, slightly gaping at the extremities; hinge with one
cardinal tooth, divided into two parts, diverging from the umbo, with
sometimes a very small laminar tooth close to its side; a deep
triangular pit near the centre, containing the cartilage; one long,
lateral tooth on each side of the umbo in one valve, received between
two in the other; muscular impressions two, lateral; palleal impression
with a small sinus.--_Obs._ This genus contains many species of
beautiful shells found in various parts of the world, some are common
in Britain. Fossil species are not numerous, they occur in the tertiary
strata. Fig. 79 to 82.
MACTRACEA. Lam. A family of the order Conchifera Dimyaria, Lam. Sect.
Tenuipedes. The cartilage placed in a trigonal pit with a small
external ligament. The genera may be thus distinguished.
1. LUTRARIA. No lateral teeth, shell gaping. The short species
constitute the genus _Ligula_. Fig. 77, 78.
2. MACTRA. Lateral teeth, shell closed. This genus has been divided
into Mactra, Mulinia, Schizodesma and Spisula, by Mr. Gray. Fig. 79
to 82.
3. GNATHODON. Teeth serrated, thick, one angular. Fig. 83.
4. CRASSATELLA. Shell thick, lateral teeth. Fig. 84.
5. AMPHIDESMA. A distinct external ligament, internal ligament
oblique. Fig. 85.
6. ERYCINA. A short tooth on each side of the cartilaginous pit in
each valve. Including Mesodesma. Fig. 86.
7. UNGULINA. Ligament flat, divided. Fig. 88.
MACULATED. (From _Macula_, a spot.) Spotted or patched. This term is
applied by conchological writers, to those shells which are coloured in
spots or small patches. In the same sense it is also used as a specific
name. As for instance, Cytherea maculata, fig. 167, c. and Hippopus
maculatus, fig. 156.
MAGAS. Sow. ([Greek: Magas], _magas_, a board, a deck.) _Fam._
Brachiopoda, Lam.--_Descr._ Equilateral, inequivalve; one valve convex,
with a triangular area, divided by an angular sinus in the centre; the
other valve flat, with a straight hinge line and two small projections;
a partial longitudinal septum, with appendages attached to the hinge
within. Differing from Terebratula in having a triangular disc, and not
a circular perforation. Magas pumilus, fig. 299. Fossil in chalk.
MAGILUS. Montf. _Fam._ Cricostomata, Bl. Serpulacea, Lam.--_Descr._
Thick, tubular, irregular, contorted; rounded above, keeled beneath,
free; apicial extremity convolute, heliciform, ovate or sub-globose;
aperture elliptical.--_Obs._ This shell when in a young state presents
the characteristics of a regularly formed spiral univalve, living in
holes in madrepores. As the madrepore increases in bulk, the animal
gives an eccentric course to the shell, in order to have its aperture
even with the surface, and leaving the nucleus or young shell behind,
fills it up with calcareous matter to reside in the open extremity of
the tube. Fig. 9, 10. Red Sea and Mauritius.
MALACOTA. Schum. OTION. Leach.
MALACOZOA. Bl. ([Greek: Malakos], _malacos_, soft; [Greek: Zôon],
_zoon_, animal.) The type or general appellative in De Blainville's
system, including all molluscous animals, excepting those with
multivalve shells.
MALDANIA. Lam. The second family of the order Annelides Sedentaria. The
only genus of shells described in this family is Dentalium, fig. 2, to
which may be added Pharetrium, König. fig. 3. It is doubtful however
whether the latter do not belong to an unknown genus of Pteropodous
Mollusca.
MALEA. Valenciennes. A genus composed of DOLIUM latilabrum, Kiener, and
other similar species.
MALENTOZOA. Bl. ([Greek: Malakos], _malacos_, soft; [Greek: en], _in_,
[Greek: temnô], _temno_, cut; [Greek: Zôon], _zoon_, animal.) Or
articulated mollusca. The sub-type in De Blainville's system,
comprehending those with multivalve shells.
MALLEACEA. Lam. A family belonging to the order of Conchifera
Monomyaria. Containing the following genera of irregular pearly
bivalves.
1. AVICULA. Hinge linear, simple, including _Meleagrina_. Fig. 163,
164.
2. PERNA. Hinge with linear grooves, including _Pulvinites_. Fig.
166, 170.
3. GERVILLIA. Shaped like Modiola, with irregular grooves. Fig.
162.
4. CRENATULA. Hinge with a series of pits. Fig. 168.
5. CATILLUS. Like Perna, but more regular and convex. Fig. 167.
6. MALLEUS. A triangular disc on the hinge, and two auricles. Fig.
165.
MALLEUS. Auct. (_Malleus_, a hammer.) _Fam._ Malleacea, Lam.
Margaritacea, Bl.--_Descr._ Equivalve, inequilateral, foliaceous,
trilobate, undulated, irregular, attached by a byssus passing through a
sinus in one valve; hinge rectilinear, lengthened by two auricles; with
a small disc under the umbones, containing the ligament, and a groove
containing the cartilage; muscular impressions one in each valve,
large, uniform, and one or two others extremely minute.--_Obs._ Malleus
Vulgaris, the type of this genus, is a most singular shell, commonly
called the "Hammer Oyster," from the peculiarity of its shape. It
belongs to the Linnæan genus Ostrea, from which it differs in being
attached by a byssus. Fig. 165, M. Vulgaris. Tropical.
MAMILLARIA. Sw. A sub-genus of NATICA, corresponding with Polinices of
Montfort, having the spire small and the umbilicus filled. _Ex._ Natica
Mamilla, Auct. fig. 327.
MAMMILLATED. (_Mammula_, a little teat.) A term applied to the apex of
a shell when it is rounded like a teat. _Ex._ Voluta Vespertilio, fig.
433.
MARGARITA. Leach. (_Margarita_, a pearl.) A genus of small shells
resembling the genus Trochus, from which it differs in having an
operculum consisting of few whorls. M. tæniata, fig. 362. Mr. G. B.
Sowerby, sen. has enumerated 15 species in a list accompanying the
figures published by the author of this manual in Nos. 132 to 134 of
his Conchological Illustrations.
MARGARITACEA. Bl. The third family of Lamellibranchiata, Bl. The shells
belonging to it are described as irregular, inequivalve, inequilateral,
black or horny without, pearly within; hinge auriculated, scarcely
developed, and without teeth. The ligament is variable and there is a
large sub-central muscular impression. This family contains the genera
Vulsella, Malleus, Pinna, Crenatula, Inoceramus, Catillus, Pulvinites,
Gervillia and Avicula.
MARGARITACEOUS. (_Margarita_, a pearl.) Pearly.
MARGARITANA. Schum. A sub-genus of Uniones, composed of species having
"one cardinal tooth." ALASMODON, Say. MYA Margaritifera, Linn.
MARGARITIFEROUS. (_Margarita_, pearl; _fero_, to bear.) Pearl-bearing.
Applied to shells which form pearls; as Meleagrina Margaritifera, or
Pearl-bearing Oyster.
MARGINAL. Near the margin or edge.
MARGINATED. (_Margo_, edge.) Having an edge or border thicker than the
rest of the shell, from which circumstance the little genus Marginella
derives its name.
MARGINELLA. (A little rim or border.) _Fam._ Columellaria, Lam.
Angyostomata, Bl.--_Descr._ Ovate, smooth, shining, with a short,
sometimes hidden spire; aperture narrow, emarginated; columella with
several oblique folds; outer lip neatly reflected.--_Obs._ This genus
of pretty little shells differs from Voluta, in the reflection of the
outer lip. The animal covers the greater part of the shell with the
mantle, and by continually depositing vitreous matter gives it a bright
polish, which, together with the delicately neat arrangement of colours
in most species, renders them exceedingly beautiful. The Marginellæ are
marine and tropical. A few fossil species are found in the
Calc-grossier. Fig. 437. M. Glabella. GLABELLA, Sw.
MARGINULINA. D'Orb. A genus of microscopic Foraminifera.
MARINE CONCHACEA. See CONCHACEA.
MARINE TESTACEA. Those shell-fish which inhabit seas, lakes, &c. of
salt water, in distinction from the _Aquatic_ Testacea, or those which
are found in rivers, ponds or stagnant pools of fresh water: and also
from the _Land_ Testacea, which live on land and breathe air. The great
proportion of shells belong to the former class, those of the latter
two classes being limited in their number, and in the genera to which
they belong.
MARINULA. King. A genus of small shells resembling Auricula and
Pedipes, described as "Ovate, sub-solid, with aperture ovate entire;
columella bidentate, uniplicated towards the base, with large
sub-remote teeth; the largest uppermost; no operculum."
MARMAROSTOMA. Sw. A genus of "Trochidæ," Sw. thus described: "Umbilicus
deep; spire of few whorls, much depressed, and obtuse; inner lip
obsolete; base even more produced than in _Senectus_, but never
distinctly channeled. M. versicolor. Mont. 176. f. 1740, 1741,
undulata. Chem. 169. f. 1640, 1641," Sw. p. 348.
MARPESSA. Gray. A sub-genus of Clausilia, C. bidens, &c. Auct. Gray's
Turton, p. 212.
MARTESIA. Leach. A genus composed of those species of PHOLAS, Auct.
which are described as short, cuneiform, nearly closed at both
extremities, having several accessary pieces on the middle of the back,
and two marginal, lower down.
MEASUREMENT. The most approved method of stating the measurements of
various kinds of shells is as follows: _symmetrical convolute
univalves_, the length is from anterior to posterior; the depth from
ventral to dorsal; the breadth, from side to side of the aperture. Of
_symmetrical conical univalves_, length, from front to back; breadth
from side to side; depth from apex to base. Of _spiral univalves_,
length, from apex to anterior of the columella or axis of the shell;
breadth, across from the outer lip to the opposite side. Of
_non-symmetrical bivalves_, the length is from the anterior to the
posterior margin; breadth, from the greatest convexity of one valve to
the corresponding part of the other; depth, from the ventral to the
dorsal margin.
MEGADESMA. Bowd. ([Greek: Megas], _megas_, great; [Greek: desma],
_desma_, ligament.) POTAMOPHILA, Sow. GALATHÆA, Lam.
MEGADOMUS. Sw. A sub-genus of Unio, thus described: "Only one lateral
tooth in each valve; cardinal teeth two; posterior hinge margin winged.
M. gigas, _Sw._" Sw. p. 378.
MEGALODON. Sow. ([Greek: Megas], _megas_, great; [Greek: odos], _odos_,
tooth.) _Fam._ Cardiacea, Lam.--_Descr._ Equivalve, longitudinal,
acuminated at the umbones, thick; hinge forming an incrassated septum
across the cavity of the shell, with a large bifid tooth in the right
valve, and one irregular and one pointed in the left; ligament long,
external.--_Obs._ The general form, the thickened hinge reaching across
the cavity of the valve and the terminal umbones serve to distinguish
this genus from Cardita, to which, however, it is nearly allied. M.
cucullatus, fig. 127.
MEGALOMASTOMA. Guild. A sub-genus of Cyclostoma, thus described:
"Cylindrical, resembling _Pupa_, but has a horny operculum; spire not
thickened; teeth or fold on the pillar none, flavula _Sw._ En. Méth.
461. f. 6, brunnea _Guild._ (_fig. 97. g. h. 1._)" Sw. p. 336. Mr. Gray
applies the name to those species which have "a groove or ridge in
front of the mouth near the pillar."
MEGARIMA. Rafinesque. A genus proposed to include species of
TEREBRATULA, Auct. which are smooth and nearly equivalve. T. lævis, T.
crassa, T. truncula.
MEGASPIRA. Lea. ([Greek: Megas], _megas_, great, and spire.) M.
Ruschenbergiana, (fig. 294) is a pupiform land shell remarkable for the
length of its spire, which consists of no less than twenty-five close
set, narrow, gradually increasing whorls. The outer lip is simple,
slightly thickened; the inner lip has a tooth on the body-whorl, and
two folds on the columella. Only one species of this singular shell is
known.
MEGATREMA. Leach. A genus composed of those species of Pyrgoma, Auct.
which have a large aperture. Fig. 33.
MELACANTHA. Sw. A sub-genus of Melania. Sw. p. 341.
MELAFUSUS. Sw. A sub-genus of Melanopsis. Sw. p. 341.
MELAMPUS. Montf. CONOVULUM, Lam. A genus composed of species of
AURICULA, Auct. of a conical form. A. conoidalis, fig. 298.
MELANIA. Auct. ([Greek: Melas], _melas_, black.) _Fam._ Melaniens, Lam.
Ellipsostomata, Bl.--_Descr._ Turrited; spire generally elongated,
acute; aperture entire, oval or oblong, pointed at the posterior
extremity, rounded anteriorly, with a kind of indistinct canal or
sinuosity: epidermis thick, generally black.--_Obs._ In common with
other fresh-water shells, the Melaniæ are frequently found with
corroded apices. This genus is known from Melanopsis by the absence of
the notch at the anterior part of the aperture. The Melaniæ occur in
rivers of warm climates. The fossil species are frequent in upper
marine formations. Fig. 313, M. subulata.
MELANIANA. Lam. (Melaniens.) A family belonging to the first section of
the order Trachelipoda. The genera contained in it maybe distinguished
as follows.
1. MELANOPSIS. Aperture notched; columellar lip thickened above;
including _Pirena_. Fig. 315, 316.
2. MELANIA. Aperture not notched; columellar lip not thickened;
including _Auculosa_, _Pasithæa_, _Io_. Fig. 313, 314, 317.
MELANITHES. Sw. A sub-genus of Melanopsis. Sw. p. 341.
MELANOIDES. Olivier. MELANOPSIS. Fer.