Cassis. 
MOLLUSCA. 
53 
Genus X V.—C A S SIS.— Bruguiere. 
Shell ventricose, gibbous, mostly subtrigonal; spire 
generally very short; aperture longitudinal, narrow, in 
some species nearly equal to the whole length of the 
shell, in others proportionally wider (in which case the 
aperture can hardly be considered as elongated) with a 
more produced spire; base of the aperture terminating 
in a short canal, abruptly reflected on its inner margin, 
which is acute; columella twisted or rugose, and pro¬ 
vided with transverse plaits; outer lip usually thickened, 
inflected, and spread over the lower part of the body, 
producing a flattened disk reaching beyond the edge of 
the lower varix, internally dentated, and in various 
species forming a varix at the completion of each volu¬ 
tion. 
1 . C. bicatinatus. — The Double-Chained Cassis, pi. 
XXXIII. fig. 7, 8. 
Cassis bicatinatus . Sowerby, Min. Conch. II. p. 117, pi. 
151, fig. 1, 2. 
Shell ovate, ventricose; spire of medium length, consisting 
of five well defined volutions, and terminating in an obtuse 
apex; whole surface traversed by numerous, transverse, promi¬ 
nent, narrow ribs, with broad intermediate furrows, decussated 
by small, slightly oblique longitudinal costa* upon the superior 
portions of the volutions, most distinct upon the central volu¬ 
tions, giving a chain-like appearance to two or three pairs of 
the furrows, but becoming obsolete below; aperture ovate, 
somewhat straitened towards both extremities, and ending in a 
short canal; pillar lip spreading broadly over the columella, 
which is slightly plaited and extending over an open umbilicus; 
outer lip thickened, rounded, reflected, and obscurely tubercu- 
lated within. 
Discovered in the Crag at Bawdsey, Suffolk, by the Rev. J. 
Lambert, of Trinity College, Cambridge. 
Genus XVI.—CASSIDARIA.— Lamarck . 
Shell obovate, ovate or oblong; ventricose; body very 
large; spire short; aperture longitudinal, narrow, ter¬ 
minating at the base in a recurved canal, which points 
upwards when the shell is placed with the aperture 
downwards; outer lip marginate, thickened, reflected, 
and frequently dentated within; inner lip expanded, 
covering the lower part of the body and columella, but 
detached from it at the base, immediately above the 
canal, which in some species is rough, granular, tuber- 
culate or rugose; outer surface generally grooved, tuber- 
culated, and covered with a thin, horny epidermis. 
1. C. carinata. —The Keeled Cassidaria, pi. XXXIII. 
fig. 1, 2. 
Cassis carinata. Sowerby, Min. Conch. I. p. 23, pi. 6, three 
upper figures. Morio carinata , Fleming, Brit. An. p. 310. 
Shell pyriform; body very large, obliquely flattened above; 
spire very short, consisting of five or six abruptly tapering, de¬ 
pressed angular volutions, terminating in an acute apex; body 
with three remote, nodulous transverse ribs, and numerous, 
close, undulous, transverse, alternately large and small strice, 
which are decussated by many lines of growth; aperture 
oblong, straitened both above and below, and ending in a nar¬ 
row recurved beak; pillar lip concave, very broadly reflected 
on the columella, with numerous tooth-like processes on its 
inner margin, and two or three on the inner margin of the 
outer lip; outer lip broad, continuous above, smooth on the 
margin, and extending over the umbilicus. 
Found in the London Clay at Highgate Hill. 
2. C. striata —The Striated Cassidaria, pi. XXXIII. 
fig. 3, 4. 
Cassis striata. Sowerby, Min. Conch. I. p. 24, pi. 6, four 
lower figures. Fleming, Brit. An. p. 339. 
Shell ovate; body large; spire small, consisting of five or six 
rounded, abruptly tapering, volutions, terminating in a sharp 
apex; whole shell covered with transverse wide-set stria?; a 
spiral ridge of transversely oblong nodules invest the superior 
portion of the body, which is also crossed by indistinct lines of 
growth; aperture greatly elongated, narrow, and contracted at 
both extremities; pillar lip much reflected on the columella, 
broad above and narrowing towards the base, which is provided 
with a narrow, slightly bent canal, and toothed within; outer 
lip broad, plicated internally, and reflected over the umbilicus 
behind. 
Found in the London Clay at Highgate Hill. 
FAMILY IV.—ALATA. 
Shell provided with a canal of greater or less extent, 
situate at the base of the aperture; the right lip changes 
its form as the animal advances in age, and is provided 
with a sinus at the lower part. 
Genus XVII—ItOSTELLARIA Lamarck. 
Shell turreted or fusiform; spire uniformly longer than 
the aperture; the superior volutions generally longitudi¬ 
nally grooved; aperture oblong, its upper part prolonged 
into an elongated narrow canal, which in some instances 
extends to the apex of the spire, and not unfrequcntly 
turns down on the opposite side ; base with a more or 
less lengthened canal, pointed beneath; outer lip in the 
infant state, thin, but becomes greatly dilated with age, 
entire, or dentated at its lower margin, or digitated ; 
outside covered with a thin horny epidermis; aperture 
provided with a thick corneous operculum of an oblong 
form, rounded at one end and pointed at the other. 
SECTION I,—OUTER LIP EXPANDED. 
1. R. macroptera. —The Long-Winged Rostellaria, pi. 
XXXIII. fig. 17, 18, 19. 
Rostellaria macroptera. Lamarck, Env. de Paris, p. 48. 
Lyell’s Elts. of Geology, p. 310, fig. 138. Fleming, Brit. An. 
p. 360. Sowerby, Min. Conch. III. p. 177, plates 298, 299, 
o 
