HALIOTIS. 
105 
these, which have no generic deficiency but that of 
the foraminal ducts. 
Did the aniiiials inhabiting the shells of one 
section differ from that which constructs the 
other, it would not prevent a generic union of 
them, according to our system ; but no such fact 
of their dissimilarity is ascertained. Some of the 
identical species open, and make use of a different 
number of their siphons. Why may not then a 
Limax be permitted to choose a water-tight re- 
ceptacle, though his fellows prefer one that is 
pervious to the winds and waves ? 
The Haliotis, from dXg, the sea, and wra, ears, is 
thus denominated on account of its ear-like form. 
The animal is attached by so adhesive a property 
to the surface of the rocks, that it requires the ut- 
most force to disengage it, though by a spontaneous 
action it is able to remove with facility from place 
to place. It is probable that in some individuals 
of this family, as in some of Helix and Patella, the 
shell does not cover the whole body of the Mol- 
luscous worm, but merely the vital organs. 
