203 

 Genus CHITON.* (Plural, Ckitones.) 



COAT OP MAIL. 



Generic Character. Shell multi valve, com- 

 posed of eight valves, rarely of seven or six ; 

 form convex oval ; the valves are arranged in an 

 imbricated manner, the margin of one being in- 

 cumbent on that of the next ; they are surrounded 

 and connected by an elastic coriaceous mem- 

 brane, which allows of the free movement of the 

 valves, it is either scaly, hairy, or spinous. 



OBSERVATIONS ON THE SHELL AND ITS 

 INHABITANT. 



The Chitons are readily distinguished from all 

 other testaceous mollusca by the form of their 

 shell, which very much resembles a small vessel 

 or boat turned upside down, and by the peculiar 

 arrangement of its moveable valves attached by 

 a coriaceous membrane. This latter substance 

 is capable of sufficient expansion and contraction 

 to admit of considerable play in the valves, so 

 that the animal can roll up its shell into the 

 form of a ball, having all the appearance of a 

 wood-louse. Thus covered by its scales it lies 

 like a pebble at the bottom of the sea, and so 



* Plate X. figure 5. 



