CONCHOLOGY. 83 



alternate pieces for the most part longitudinal ; sides naked ; 

 branchiae disposed around the body ; foot cleft longitudinally by a 

 deep furrow. 



Shell. Each valve with strise radiating from its apex ; the 

 margins serrated ; the base of the last valve obtuse. The testa- 

 ceous plates of this genus are never joined like those of the chiton, 

 so that the animal can move in every direction. Upon the con- 

 traction of the animal after death, however, these valves become 

 nearly united. Inhabits the seas of New Holland. Two species. 

 Chitonellus striatus. Chitonellus larvseformis. 



3. Genus Chiton, 

 minimal. Body creeping, ovate oblong, convex, round at both 

 extremities ; marginated with a coriaceous skin ; the back covered 

 by a longitudinal series of testaceous, transverse, imbricated, and 

 moveable plates ; head before, sessile, with the mouth placed telow, 

 destitute of tentacula or eyes ; branchiae placed round the body, 

 imder the margin of the skin ; and orifice at the posterior 

 extremity. 



Shell. Eight imbricated valves, nearly smooth, slightly cari- 

 nated, and rounded at the margins; summit more or less marked 

 and curved, by longitudinal elongations. Inhabits the British 

 and American coasts. Sixty species. 



Chiton fulvus. Chiton gigas. 



C. pisceus. C. squamosus. 



C. ruber. C. Peruvianus. 



C. laevis. C. tesselatus. 



C. spinosus. C. capensis. 



C. fascicularis. C. Carmichaelis. 



C. marginatus. C. echinatus. 



C. crinitus. C. striatus. 



C. siculus. C. lineolatus. 



C. niger. C. chilensis. 



C. spiniferous. C. tuberculatus. 



C, coquimbensis. C. hispidus. 



C. lumingii. C. thalassimus. 



C. granosus. C. porosus. 



