160 < HITON. 



resemblance to the West Indian smooth Chiton, (\ 

 but it differs in the plan of coloring both inside and out, the West 

 Indian species lacking the dark blotches upon the bases of the 

 sutural-plates, which are so characteristic of Icevigatus. The 

 marmoratus, morever, has a proportionately wider sinus, the straight 

 toothed space between the sutural-plates being half as long as each 

 plate, whilst in Icevigatus it is only one-third as long. This last 

 character, together with the internal coloring, will always distinguish 

 the two species. 



C. ALBOLINEATUS Sowerby. PL 32, fig. 57. 



Shell oblong, parallel-sided, moderately elevated, carinated, 

 smooth ; lateral areas, end valves and dorsal keel black, marked with 

 -i-nile radiating lines. Sides of the central areas light olive- 

 green, some of the valves occasionally black. 



The lateral areas are a little raised; entire surface most minutely 

 granulated in the usual quincuncial pattern. Beak of posterior 

 valve anterior. 



Interior light blue, the sutural plates paler. Anterior valve 

 having 15-16, central valves 1, posterior valve 16-17 narrow slits ; 

 teeth strongly pectinated. Eaves narrow, short, spongy. Sinus 

 denticulate. 



< iirdle firm, blue-gray, compactly covered with convex-flattened 

 polished imbricating scales. 



Length 35, breadth 18 mill. 



Todos Santos Bay, L. California (R. E. C. Stearns) ; Mazatlan 

 (Cpr.) ; Acapulco (Ruschenberger.) 



C. albolineatus SOWB., Zool. Journ. iv, p. 368 ; in Zool. Beechey's 

 Voy., p. 149, t. 40, f. 4 ; Conch. 111., f. 39. C albUineatns Ri 

 Conch. Icon., t. 2, f. 11. Lophyrus albolineatus CPR., Maz. Cat., p. 

 191. 



The apparently smooth surface and the conspicuous snowy stripes 

 render this a very distinct specific type. Each scale of the girdle 

 when examined under a lens is seen to be of a delicate blue-green 

 color, edged broadly with white. 



C. MAONIFICUS Deshayes. PL 30, figs. 23, 24. 



Shell large, oval, moderately elevated or somewhat depressed, the 

 dorsal ridge indistinctly carinatrd. -id. --lopes a little convex. Color 

 Murk, H'itli minute blue dots scattered rather thickly over the valves; 

 girdle bla<-k. 



