ISCHNOCHITON. HI 



Ch. cateuulatus SOWK., P. Z. S. 1832, p. 104; Conch. Illustr. f. 

 145. REEVE, Conch. Icon. t. 20, f. 130. Ischnochiton catenulatm 

 CPU., MS. 



The single specimen before me is whitish, sparsely variegated with 

 brown, the girdle ashen-bluish. The sculpture of the valves is 

 more like that of /. striolatns Gray and adamsii Cpr., than any- 

 thing else, having exactly the same pattern, but not quite so distinct. 

 The girdle has conspicuously striated scales. 



* * Species with convex, smooth scales. 



The following species were referred by Carpenter to "Lepido- 

 pleurus," but they are closely allied to the present group. 



I. DISPAR Sowerby. PI. 18, figs. 47, 48. 



Shell oval, smooth, ashen varied with whitish and black. Cen- 

 tral areas smooth, posteriorly longitudinally subsulcate ; anterior 

 valve, lateral areas, and posterior area of the posterior valve granu- 

 lous. Girdle granose. Length 25, breadth 12| mill. (/SW6.) 



Island Saboga, Bay of Panama, under stones on the shore. 



Chiton dispar SBY., P. Z. S. 1832, p. 58; Conchol. Illustr. f. 25. 



REEVE, Conch. Icon. t. 18, f. 96. Not Ischnoradsia dispar 



Carpenter MS. Chiton proprius REEVE, Conch. Icon. f. 161. C. 



phus REEVE, Conch. Icon. t. 25, f. 121. 



The name has been suggested by the circumstance of the central 

 areas being quite smooth, while the lateral areas are covered with 

 granules. ( G. B. Sowerby.) 



The description given by Sowerby differs entirely from the spe- 

 cies which I take to be the Ischnoradsia dispar of Carpenter's MS., 

 and indicates a form very similar to Carpenter's L. adamsii. 



Carpenter writes of the type of C. proprius Rv. as follows : One 

 specimen, smashed ; " West Coast of America," Dr. A. Sinclair, R. 

 N. This is exactly like the Lepidoplenrus dispar, having very 

 large, smooth scales. Reeve's C. picus is also said by Cpr. to be a 

 synonym for I. dispar. 



I. ADAMSII Carpenter. PI. 18, figs. 51, 52, 53, 54, 55. 



Shell resembling L. diapar ; pale red-brown, irregularly streaked 

 and maculated with darker, sometimes ornamented with white spots 

 at the diagonal region. Jugum scarcely acute ; central areas and 

 terminal valves conspicuously granulous ; lateral areas irregularly 



