166 ( HITON. 



( .irdle (pi. 32, figs. 53) covered with solid, convex, subcarinated 

 imbricating scales. Length 68, breadth f>0 mill. 



Gun?/ . II >>> Mexico, to Panama and West Coliunhin. 



Chiton stokesii BROD., P. Z. S., 1832, p. 25. S,,\vi;.. Conch. 



mufltr., f. 24. REEVE, Conch. Icon., 1. 1, f. 4. M..I:< H. Mai. 151. 



v jj p 171; Chiiun jtnttilu* Sown., Charleswortli's MULT. Nat. Ili.-t. 



. p. _".! : Conch. Illustr.,f. 134. RKKVE, Conch. Icon., f. 30. 



>il,fn.< CPU., J/\ 



The sculpture of the lateral areas is peculiar, being something like 

 the meshes of a stretched net, but the cords or riblets are irregularly 

 irranulose. In uniting the C. patulus of Sowb. to stokesii, I quite 

 agree with Carpenter, who writes as follows: The form patulus is 

 typically " engine-turned " on the terminal valves, with strong ruga? 

 on the sides, and larger scales on the girdle. A young specimen 

 sent by Mr. Cuming has only 18 slits in the tail plate. The typical 

 stokesii has the terminal rugae radiating, and sometimes a row of 

 color tints at the sutures. The bulk of the Panama and San Juan 

 i niens (of which I have examined many hundreds) are so 

 variously intermediate between the two forms that I find it impos- 

 sible to separate them even as varieties. The scales are extremely 

 deciduous, and specimens in good condition are not often found. 

 It was often the custom of Mr. Cuming to select extreme forms for 

 his cabinet; and these being described and figured as the normal 

 types of species are very apt to mislead students who work by single 

 specimens. 



( '. vi 1:1.1 i. \ rrs Sowerby. PI. 32, figs. 54, 55, 56. 



Shell ohlonir, parallel-sided, rather elevated, the dorsal ridire ear- 

 inated, side-slopes straight. Lateral areas and end valves olive- 

 brown, or like the central area< which are green, longitudinally 

 cl..iided with blackish : girdle jinn ami W/W. t ransversely or longitu- 

 dinally banded. 



The lateral areas are raised and -culptur.-d with rwmenut s -10) 



ifiti'i rifift.'t-*, irli ic/i /mi' "-// //, sji/it or branch. Central 



areas sculptured with longitudinal rihlets which at the sides diverge 



a little and are nearly as coarse as those of the lateral areas, hut 



finer and parallel to the rid^e toward the middle. Km! 



valves having dose radiating riblct> : ap. \ of tail valve ante) i 



In-ide dark I>1> sutural-plates hi'jh. blue-irr- en. Sinus 



angular and tootln-d. Ant-.i-r valvi- liavinjr '1\-1'1, <-cnh*<il 



