160 CHITON. 



resemblance to the West Indian smooth Chiton, C. marmoratus; 

 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. ALBOLTNEATUS Sowerby. PL 32, fig. 57. 



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

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

 snow-white 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. 



Girdle 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. albilineatus REEVE, 

 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. MAGNIFICUS Deshayes. PI. 30, figs. 23, 24. 



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

 dorsal ridge indistinctly carinated, side-slopes a little convex. Color 

 black, with minute blue dots scattered rather thickly over the valves; 

 girdle black. 



