55 



DEFINITIONS and DESCRIPTIONS 



OF 



THE GENERA. 



MULTIVALVES, 



CHITON. 



(See Plate III. fig. 1.) 



Valves many ; disposed in an imbricated man- 

 ner, 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 resemble? theOniscus entomon, 

 or marine woodlouse, and has often been mistaken 



