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MOLLUSCOUS ANIMALS. 
Eyes nearly seated on the base of the tentacles. 
The American and European species are equally viviparous ; and the young are covered with bands of 
hairs differing in number in the different species. 
AMPULLARIA. 
The mouth simple, thickened at the edge, free above; the gills formed of a series of triangular lamina 
forming a line down the right side of the branchial cavity, close by the side of the colon and ovarian tube. 
There is also a small mass of lamellae at the outer left angle of the cavity ; the rest of the cavity is filled with 
a large fleshy bag, open by a wide slit ; tentacles conical, elongate ; eyes on short tubercles, but close to the 
outer base of the tentacles. The trunk short ; front of the side expanded into short, conical, tentacula-like lips ; 
foot simple, folded across. From the tentacles on each side to the base of the edge of the respiratory cavity 
there is continued a broad flat plate which is largest on the left side, and which appears to be bent up so 
as to form a canal to conduct the water to the respiratory cavity ; the one on the right side is folded, and 
gives origin to a fleshy ridge, which extending up the right side, close to the side of the colon, is continued 
to the tip of the respiratory cavity, the use of which does not very readily appear. The penis conical, elon- 
gated, near the tentacles, and enclosed in a bivalve sheath in the thickened margin of the right side of the 
collar. 
The reversed species ( Lanistes , De Montfort) are very like the others ; the front of the head is bifid ; the 
conical process of the front of the head and the tentacles are spirally twisted; there is a plate on each side of 
the body forming a canal to the neck ! the penis contracted into the right side of the edge of the mantle, and 
there is a distinct air bag.—The operculum is horny, with a subcentral nucleus. 
The Ampullarice are capable of living a long time out of water, for M. Caillaud brought some specimen 
to Paris alive from the Nile ; he kept them in dry saw-dust. 
