174 CHITON. 



are rather strongly arched backward, and the broad sinus is remark- 

 able for the absence or obsolescence of teeth. The interior, except 

 just behind the sinus, is smooth ; the callus in each valve is heavy 

 and smooth. Figures 14, 15, 17 are drawn from Auckland, N. Z. 

 examples, furnished by Mr. G. W. Wright. 



C. SINCLAIRI Gray. PL 36, figs. 1, 2, 3. 



Shell oval, rather elevated, the dorsal ridge rounded, side-slopes 

 rather straight ; brown-black, each valve irregularly and raggedly 

 striped with whitish ; the head valve pale with dark rays. Some- 

 times the white predominates. 



The lateral areas are raised and sculptured with three or four 

 radiating granose ribs, often subobsolete. Central areas smooth in the 

 middle except for a few groivth-wrinlcles, but having fine short longitu- 

 dinal riblets at the sides in front of the diagonal line. These riblets 

 are sometimes almost obsolete. Head-valve sculptured at first with 

 about 15-18 granose riblets, but as these have a tendency to split as 

 the valve grows, the number m a grown specimen is usually 24-30. 

 Tail-valve having a low, obtuse mucro, decidedly in front of the 

 middle. 



Interior bluish. Sinus rather wide, denticulate, the area behind 

 it porous. Anterior valve having 11, central valves 1, posterior 

 valve 14 slits; teeth obtuse, strongly crenulated. Eaves broad, 

 spongy. 



Girdle (pi. 36, fig. 3) covered with large, convex scales, which 

 are very finely, sharply striated. 



Length 28, breadth 18 mill. 



Length 17, breadth 11 mill. 



New Zealand (Sinclair, Hutton, Wright.) 



Chiton sinclairi GRAY, in Diefienbach's Travels in Ni Z, ii, p. 263 

 (1843). HUTTON, Trans. N. Z. Inst. iv, p. 177; Man. K Z. Moll, 

 p. Ill (1880). SMITH, Zool. 'Erebus' and 'Terror,' p. 4, t. 1, f. 

 17. REEVE, Conch. Icon., t. 22, f. 143. 



The smooth, polished central areas, grooved only along the 

 diagonal line at the sides, and the granose-ribbed lateral areas and 

 end valves are characteristic, and remind one of the West Indian (7. 

 viridis. The black-and-white coloring also is rather constant. The 

 sculpture of the side-areas varies greatly in strength. This species 

 has been reported from Tasmania, but on doubtful authority. 



