180 MOLLUSGA. 
nus, the spongy body is capable of changing its dimen- 
sions, and enabling the animal to sink or rise in the water 
at pleasure. When irritated, the animal ejects a purple fluid 
from the cellular margin of the cloak above the gills, not 
unlike the Aplysia. This species was added to the British 
Fauna by the late Miss Hutchins. 
Genus VeLuTInA.—Foot simple. This genus was form- 
ed by us for the reception of the Bulla velutina of Miller, 
(Zool. Dan. tab. ci. f. 1, 2, 3, 4), the Helix levigata of Bri- 
tish writers. The foot is destitute of lid or appendage, and 
is broad before, and pointed behind. The tentacula are two 
in number, short and filiform, with eyes at their external 
base. The head is broad and short. In addition to these 
characters given by Miiller, we have been enabled to add 
the following, from a specimen, somewhat altered, which was 
found in the stomach of a cod-fish. The animal adheres to 
the shell by two linear muscles, one on each side the cloak. 
The branchial cavity is towards the left side. The tongue 
is spinous, narrow, with its free extremity spiral. Eyes 
rather behind the tentacula. Penis exserted on the right 
side of the neck, immediately behind the eye. Cloak large 
in proportion to the size of the foot. We have termed the 
genus Velutina, bestowing on the species the trivial name 
vulgaris. 
In the following groups the anterior margin of the aper- 
ture of the shell is canaliculated. This groove in the aper- 
ture of the shell is produced by the anterior margin of the 
cloak being extended over the opening into the gills, for 
the purpose of acting like a tube or syphon, in conveying 
the water to and from the branchial cavity. The species are 
considered as oviparous, with distinct sexes in separate in- 
dividuals. 
Sanit 
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