‘94 ZOOLOGY. 
Tribe Decacera. 
Fam. 2. Sepiide. Sepia (pl. 16, fig. 77) has the body surrounded by a 
narrow fin ; and of the ten arms, two are pedunculated and longer than the 
rest. A light friable oblong-oval and spongy shell, usually named “ cuttle- 
bone,” is contained within the back. The contents of the ink-bag in this_ 
animal are dried and used by painters under the name of sepia. - 
Fam. 3. Loligide. Loligo (L. loligo, Linn., pl. 76, fig. 76) has the body 
slender, with lateral fins, the shell thin, horny, and translucent; twa 
pedunculated arms longer than the rest, and the eyes are without a lid, but 
covered with a transparent membrane. Its motion backwards through the 
water by means of its funnel, is extremely rapid, and it sometimes throws 
itself out of the water, or mpon land. The species are much used for food, 
especially in China. 
fam. 4. Loligopside. Loligopsis has a slow motion, the shell is 
corneous, the body slender and translucent, and has few muscles. 
fam. 5. Teuthidide. Onychoteuthis (already referred to) has a corneous 
internal shell, a slender body, with a triangular fin upon each side posteriorly, 
uniting upon the back. 
Fam. 6. Belemnitide. Shell corneous, conical, largest anteriorly, and 
containing a series of chambers, posteriorly pierced by a siphuncle, and 
inserted in a hard case or belemnon, which is generally pointed posteriorly. 
The family is extinct, but its remains are abundant in a fossil state in the 
oolitic and cretaceous formations. 
Fam... Spirulide. The genus Spirula (S. spwrula, pl. 76, fig. 13) is the only 
one in the family, and until recently it contained but a single described species. 
The shell is a thin open spiral (not twisted longitudinally as represented in the 
figure), with numerous partitions concave externally, through which a small 
ventral siphuncle runs. The shell is internal, at the posterior extremity of the 
body. There are ten arms, of which two are larger than the rest. The 
common species inhabits the Atlantic and Pacific Oceans, and although the 
shell is common, the animal is very rare, and requires further examination. 
The second order, Zentaculifera, contains two families: Vautelede, and 
Ammontide. ~ 
fam.1. Nautilide. Inthe genus Vautilus (lV. pompilius, Linn., pl. 76, 
jig. 16), the shell is spiral, many-chambered, the partitions transverse, 
concave externally, their margins simple; a central siphuncle passing 
through them; the whirls in contact, the last enveloping the preceding ones. 
Nautilus pompilius is the best known species; the shell is nacreous, orna- 
mented with irregular reddish bands, the umbilicus closed. It is six or 
eight inches in diameter, and inhabits the Indian and Pacitic Oceans. A 
second species is known, JV. wmbzlicatus, which is much rarer than the 
former, and has the centre of each side widely umbilicate, so that the 
whirls can be counted. The history of the order is taken from J. 
ponypilius. The animal is contained in the last open chamber of the shell ; 
it has a pediform appendage for creeping, and when it walks upon the 
bottom, the aperture is downwards. The jaws are like a reversed parrot 
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