MOLLUSCOUS ANIMALS. 
121 
PERSONA. 
The foot very large, expanded, forming the expanded base round the mouth as in Cassis. The internal 
varices are permanent, as‘in that genus, and the pillar is very tortuous, with two very strong plaits in front — 
the front one is longest, and irregularly toothed ; the cavities of the upper whorls are quite filled up, and the 
cavities of the succeeding ones are furnished internally with concave shelly septa. 
These shells have generally been placed with Triton, but they differ from them in the large size of the 
foot of the animal, and the expanded base and permanent varices in the shell. They agree in their resem- 
blance in the shell and mouth to that genus. 
CASSIDARIA. 
The foot is small, oval, folded across. The proboscis cylindrical, conical, long, slender. The tentacles 
subulate, thick, placed on the sides of the base of the proboscis, with the eyes on the outer side of their base. 
The male organ large; the respiratory canal rather short. The operculum is oblong, large, horny, solid, nearly 
straight on one side, and rather narrow in front, like that of Buccinum in shape. 
Cassidaria acuta. 
Shell ovate, fusiform, ventricose, white (with two or three brown spiral bands) ; spire conical, acute ; 
whorls longitudinally transversely ribbed, subnodular, with an acutely angular subposterior ridge ; outer lip 
thickened externally, ten or twelve toothed internally, inner lip slightly raised, w’ith rather distant cross 
ridges. 
DOLIUM. 
The foot very large, expanded, not folded, rounded behind, without any operculum. The proboscis very 
long, subcylindrical, tubular, situated in a deep cavity, on the edge of which are placed the tentacles. The 
tentacles subulate, placed on each side of the base of the trunk, and with the eyes placed on short tubercles at 
their outer base. The male organ is very large, and like that of Buccinum undatum in shape ; respiratory 
canal short. 
I have been enabled to examine the male of D. Pomum and two females of J). Perdix. In the former the 
proboscis is elongated, conical, and in the latter it is very large and trumpet-shaped, with a short exposed 
hooked tongue on the top. The three specimens of B. Pomum varied in their tentacles ; one had both the 
tentacles perfect, one had no tentacle on the right side, its place being occupied by the penis, and the last 
had none on the left, but a large one on the right side before the male organ. All the specimens of the other 
species being female, I could not observe whether it was liable to similar variations. 
HARPA. 
The foot very large, expanded, nicked even with the head on each side in front, and produced and 
keeled above behind, without any operculum. The edge of the mantle is thin, and not reflexed, and furnished 
with a rather large conical respiratory canal. The trunk is long, conical, hard. The tentacles are conical, 
thick, rather close together at their base ; their base is thickened for about one-third of their length, and at the 
outer tip of the base the eyes are placed. The male organ is large and conical. When alive these animals 
are orange-spotted ; they live on sand-banks, and are taken with meat attached to lines, or with nets attached 
to a rake. They are said only to feed at sun-rise. 
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