DEFINITIONS AND DESCRIPTIONS 
OF 
THE GENERA. 
— ^ — 
MULTIVALVES. 
CHITON. 
(See Plate III. Fig. 1.) 
Valves many; disposed in an imbricated manner, 
or with the edges one over another, along the back. 
The general form of the shell is convex-oval, 
and the margins of the valves are connected by an 
elastic, coriaceous cartilage, often scaly, hairy or 
spinous, which permits the free motion of the 
valves, or segments, in a longitudinal direction. 
The Chiton much resembles the Oniscus ento- 
mon, or marine woodlouse, and has often been mis- 
taken for it. It is capable, in the same manner, of 
rolling itself into a perfect ball. 
