CHAP. XXXV. 



UNIVALVES: 

 PATELLA ; Limpet, or Dish Shell. 



Q. DOES not the Patella resemble a cone, 

 though mostly without a spire? 



A. It does so, and an attentive consideration 

 of this peculiarity will sufficiently distinguish the 

 Patella from the Haliotis. These curious shells, 

 as the name Patella signifies, assume the shape 

 of various little dishes, and are firmly affixed by 

 their tenants to the rocks, with the apex 

 uppermost. 



Q. Do they leave their stations ? 



A. Occasionally, by means of a sort of leg, 

 which is attached to the under surface of the 

 animal. This appendage also embraces part of 

 the interior, and when the animal has occasion to 

 change its place of abode, it projects the foot 

 from beneath the shell, which gently erects itself 

 on one edge, as if to diminish friction, and by a 

 sudden spring the animal actually advances to a 

 considerable distance. 



