ill ION. 



posterior valve I !i 20 " i'' th \vid-, 



blunt, pectinated ; bort, narrow. BpODj 



( ;irdle compact!;, I with solid, */*//////;/ convex scales (pi, 



82, li.ir. 



ofena /.' ft/omw ; ';>///'"/ Calij 



- WB. in Charlesworth's Mag. Nat Hi>t. 1840, 

 P. L'!I ; Conch. Illustr.. 1'. 132.- REEVE, Conch. Icon., t. 21, f. 140. 



Thi> species is allied to ('. N/fi/w//, hut differs in bring narrower, 

 more elevated, dilierently colored, in having the riblets iim-r. inoj-e 

 nunuM-oiis and less anastomosing, in the color of the interior and in 

 the iinmher <>f .-lius which is much Lfi'eater in the end valves of this 

 species than in those of C. ttnketii, and in some of the intermediate 

 valves there are two slits in one or both sides. The entire surface, 

 as usual in this genus, is microscopically granulated. The girdle- 

 scales are liner and smoother than in <". s/o/r*//, and the sutural- 

 plates are different in form. 



A square mm. of the girdle is shown by the dotted line in fiir. ~><>. 



It has been reported from Australia, but erroneously. Many spec- 

 imens are before me from the localities given above. 



The remarkable feature of this species is that it forms a perfect 

 transition between the restricted genus Chiton and the section 

 /iV/>/</. Some specimens have two slits in one end of one valve 

 only; others have two slits in the majority of the valves; and 

 scarcely two are alike in the arrangement of 1-and 2-slit insertion- 

 plates. I have examined the interior in about a dozen individuals 

 and have always found at least one insertion-plate Radsioid, but 

 probably a larger series would reveal specimens with the normal 

 plates of ( 'lit t<> a >. x. 



C. GRAN08U8 Frembly. PI. 30, figs. 27, 28. 



Shell oval-oblong, moderately elevated, scarcely earinated, the 

 side-slop-> somewhat convex. Black, having a white stripe <t e<icl> 



i the central l'm<\ clouded with whitish between the .-tripes. 

 Lateral areas bearing three or/'"/.-- "'</</-///< on a 



ih ground: <,////// iirea* hnrintj a narrow smooth dorsal band t 

 the sides (pleura) covered "/'/// dose, fine longitudinal -.vhidi 



are more or less crenulated by the gn\\ th-lines. Knd valves hav- 

 ing rounded pustules in radiating rows or irreguhirlv scattered; 

 umbo of tail valve near the front margin. 



