CHITON. 13 



KIDNEY SHAPED CHITON. 



12. Chiton amiculatus. Ch. testa octovalvi reneformi fragilissima, corio 



extus scabro obducta. Linn. Gmel. p. 3206. 

 Shell of eight valves, kidney shaped and very brittle, covered externally 



with a rough coriaceous membrane. 

 Pallas, Nov. Act. Petr. 2. p. 241. t. 7. f. 26—30. 



The kidney shaped valves is a striking peculiarity in 

 this species, and more characteristic than the external 

 covering, since the shape of the shell will remain when 

 the membrane is gone. 



Pallas says, that it inhabits the Kurile Islands, and is 

 more than six inches long. 



CHESNUT CHITON. 

 PI. 2. /. 2, 3. Mr. Jennings. 



13. Chiton castaneus. Ch. testa octovalvi glaberrima, supra castanea, intus 



rosea. 

 Shell of eight valves, very smooth, chesnut above, rose colour within. 



Shell oval, valves perfectly smooth, except some faint 

 indications of striae, running down the dorsal triangles 

 towards the margin. Marginal triangles uniformly 

 depressed near their insertion in the coriaceous border. 

 Colour deep chesnut; where decorticated the shell 

 appears white, and the marginal triangles and extreme 

 valves, toothed at the base, and striated longitudinally. 

 The valves within side the shell are of a fine rose colour, 

 edged with white. 



PI 3.f. 2^3 

 are the young of the same shell, which from its different 

 size and colour, might readily be mistaken for a distinct 

 species. At the apex of each valve, where the ridge of 

 the shell is decorticated, there appears a small whitish 



