46 8CHIZOPLAX. 



Yar. M ITAU.II Cjir. 



Umbo flatter; valves broad, non-swelling, squared at the sides, 

 and not beaked or waved. Posterior valve having 11, central 1, 

 anterior 8 slits. 



Habitat same as hartivegii. 



Chiton uutt'illii CPR. P. Z. S. 1855, p. 231 ; Trachydermon n., 

 ( !!:. Suppl. Rep. B. Asso. 1863, p. 649 ; CfioBtopleura n., CPR. MS., 

 in Dall, Proc. U. S. Nat. Mus. 1878, p. 330. 

 I am unable to separate this form from hartwegii, as transition 

 linens are numerous. 



T. I.IPUNCTATA Sowerby. PL 14, fig. 90. 



Shell ovate, smooth ; green, variegated with black and white ; 

 margin concolored, generally having a white spot on each side 

 between the first and second valves, marginal ligament smooth. 

 I. ngth 12, breadth 6} mill. (Sowb.~) 



Liner Lobos Island, Peru, under stones at low water. 



C. bipundatus SOWB. P. Z. S. 1832, p. 104; Conch, lllustr. f. 27. 



This species varies much in coloring, some specimens being nearly 

 Mark, others light green, and some much and prettily varied. In 

 almost all a white mark may be observed on the margin just 

 behind the anterior valve. (Sowb.) 



Carpenter's notes on the types areas follows: Posterior valve 

 having 9, central 1, anterior valve 9 slits; teeth smooth, stumpy ; 

 eaves very short, spongy. Girdle smooth with extremely short, 

 re<l hairs, and two white spots at the sutures of anterior valve. 

 Valves beaked, but they seem to have no pattern of sculpture, only 

 a very close quincunx (arrangement of granules). Looks like 

 a Tr>t<-l,>j<Jermon without scales. The mucro is in front of the 

 middle, the slope behind it concave. Color greenish, generally 

 with u white blotch behind. 



Length 12, breadth 7 mill. 



Congeneric with and very like a small nuttaUii. 



< -mis IX. SCHIZOPLAX Dall, 1878. 



Schizoplax DALL, Proc. U. S. Nat. Mus. p. 2, Jan., 1878 ; 1. c. p. 

 328. ( !p& M.S. Type Chiton brandtii Midd. 



Shell and girdle as in Tonicella, except that the median valves 

 have a central jugal slit filled with cartilage, narrower in front; 



