Pvn H,i I'UitlS

CYPRINA. 307
side ; and through it water is introduced into the vas-
cular portion of the foot, when the latter becomes suffi-
ciently distended to make a passage in the sand for the
whole animal and shell. According to Dr. Johnston it
is carnivorous : he states that he once found in its
stomach "the undigested remains of a large green
Nereis, enveloped in a pulp which was certainly too
consistent to have been the sediment from water, how-
ever loaded with animalcula." This, however,
contrary to the known habits of the Aeephala, that the
admission and detention of the Annelid may be ac-
is so
counted for in some other way. Possibly, having
entered into the body of the Cyprina, it could, not get
out, and thus suffered a lingering death. The contrac-
tion of the larger tube, or the valve of the smaller one
might have prevented its escape in that direction ; and
the stomach has no other vent. At any rate, the fact
of the Nereis being " undigested " would lead to an
inference that such was not the ordinary food of the
Cyprina. The same excellent naturalist also remarked
that this mollusk and the horse-mussel often swallow
the bait of the fisherman. It is true that they are fre-
but their palps are not
and I should be rather disposed to attribute
quently caught by the hooks ;
prehensile ;
their capture to the fishing-lines being dragged by the
tide or the motion of the sea, and to the hooks coming
into accidental contact with the gaping shell-fish. C.
Islandica is apt to be infested by species of Pinnotheres
and Planaria.
Lister first described this shell. Linne, and after him
Pennant, seem to have confounded it with Venus merce-
naria. It is the Pectunculus crassus of Da Costa, and
Cyprina vulgaris of Brown. The latter name was adopted
in his
'
Genera of Recent and
by Mr. G. B. Sowerby,