50 CALLOCHITON. 



lateral areas not prominent, with no radial markings ; umbones 

 small, pointed. 



Girdle. With delicate flat elongated scales. 



Gills. Extend along whole length of foot, about thirty in num- 

 ber on each side. 



Color. Central areas yellowish, obscurely mottled with orange ; 

 on some valves there are a central and a lateral pair of pale lines. 

 Lateral areas and terminal valves of a uniform dull orange color, 

 and uniformly spotted with minute black dots, which are absent 

 from the central areas, the posterior border of the valves is orna- 

 mented with alternate lighter and darker spots. Ligament brown- 

 ish, with a few irregular small white flecks and five large white 

 spots, four very large spots extending from the points of junction 

 of the first and second and seventh and eighth valves respectively 

 to the edge of the girdle; the fifth spot being in the median line 

 posteriorly. (Haddon.) 



Interior. Posterior valve with 14, anterior 16 and median valves 

 with 3 slits. Teeth solid, separated, propped outside, bifid or 

 3-shaped. Eaves very spongy, simple, short. Sinus small, wide ; 

 sutural plates united ; girdle normal. (CJpr.) 



Sydney; Port Jackson; Botany Bay ; Australia ; (and New Zea- 

 land?). 



C. platessa GLD., Proc. Bost. Soc. N. H. ii, 1846, p. 143; U. S. 

 Expl. Exped. p. 320; atlas, f. 434, 434a, left hand, under Ch. fru- 

 ticosus. Lepidopleura platessa GLD., Otia Conch, p. 242. Callo- 

 chiton platessa Old., CPR., mss. HADDON, Challenger Rep. p. 1 5. 

 Chiton crocinus Rve., Conch. Icon. t. 22, f. 146, 1847. Chiton ver- 

 sicolor A. AD., P. Z. S. 1852, p. 92, t. 16, f. 5. Lep to chiton versico- 

 lor, ANGAS, P. Z. S. 1867, p. 223. 



There is an error in the lettering of Gould's plate, the figures 

 being numbered 434 instead of 431. There is considerable varia- 

 tion in coloring. C. versicolor, which Carpenter considered a syn- 

 onym, is represented in pi. 10, fig. 6. C. crocinus (pi. 10, fig. 7) is 

 a larger form, length 35 mill., said to be from New Zealand. 



C. PRINCEPS Carpenter, n. sp. 



Shell large, very flat, oval ; jugum angulate ; red, streaked with 

 paler and deeper. Posterior valve large, very flat, the median 

 umbo inconspicuous. Lateral areas hardly defined ; central valves 



