HABITATIONS OF MOLLTJSKS. 23 



skin or a hairy kind of garment. This curious appendage 

 is particularly obvious in different species of Troclms, Conns, 

 Triton, TJnio, and others, which not unfrequently conceal 

 beneath such extraneous coverings the most beautiful 

 designs and painting. Thus many Limpets, when dis- 

 robed of their garment by the application of nitric acid, 

 present an under-surface resembling the finest tortoise-shell, 

 blended with burnished gold. The Trochics Iris conceals 

 in like manner a splendid metaUic lustre; and numerous 

 species of the genus Unio, which are covered with a brown 

 or green epidermis, reveal a brilliantly tinted and pearly 

 surface, glowing with the colours of the rainbow. 



St. Pierre, with his accustomed elegance of thought, con- 

 jectures that nature has veiled the beauty of these singular 

 productions, hi order to preserve it for the admiration of 

 her sons ; that she has placed them among the shallows of 

 the sea-shore, where the agitated element polishes them by 

 the continual motion of its waves, in order to throw them 

 within their reach ; and that, as if to excite the astonishment 

 of untutored men, she places shells of unrivalled lustre in 

 regions exposed to the fury of the elements, while at the 

 same time she presents the poor Patagonians with spoons 

 and cups, the lustre of which surpasses the richest plate of 

 polished nations. 



