96 ISCHNOCHITON. 



Carpenter gives the following notes: Anterior valve with 9, 

 central valves 1, posterior valve 9 slits; teeth typically Ischnoid ; 

 sinus deep, broad, channelled, flat ; eaves moderate. Jugum obtuse, 

 elevated; central areas very conspicuously granulated in quincunx, 

 passing somewhat into the V-sculpture ; lateral areas conspicuously 

 raised, concentrically wrinkled, " thumby." Mucro central. Gir- 

 dle with pretty large, broad, thin, distinctly striated regularly 

 imbricated scales. Length 22, breadth 10J mill, ; divergence 106. 



The peculiarity of the shell is the elongation. It is probably 

 Australian and belongs to the I. contractus group. 



I. USTULATUS Reeve. PI. 24, figs. 11, 12 (enlarged). 



Shell elongately ovate ; terminal valves and lateral areas radi- 

 ately ridged ; ridges wrinkled, here and there grained and bifur- 

 cated ; central areas very minutely reticulated. Burnt brown. 

 Ligament granosely coriaceous. (Reeve.) 



Australia. 



C. ustulatus REEVE, Conch. Icon. t. 17, f. 102, March, 1847. 

 Ischnochiton ustulatus CPR., MS. Lepidopleurus ustulatus ANGAS, P. 

 Z. S. 1867, p. 222. 



Carpenter briefly notes that the scales of the type specimens are 

 rather gravelly and irregular, very small, but apparently a little 

 striated. The drawings of scales and valves given on my plate 

 were prepared for Carpenter, presumably from specimens in the 

 collection of Mr. Win. A. Haines, of New York City. 



I. CARINULATUS Reeve. PL 23, figs. 94, 95. 



The finely keeled Chiton. Shell oblong-ovate, terminal valves 

 and lateral areas of the rest concentrically and radiately somewhat 

 obscurely ridged and sculptured with obtuse granules arranged in 

 wrinkles, central areas also granulated, smooth in the middle, 

 peculiarly keeled at the summit ; ruddy rose ; ligament finely 

 squamately coriaceous. (Eve.) 



Tasmania. 



Ch. carinulatus REEVE, Conch. Icon. t. 23, f. 158, May, 1847. 

 Ischnochiton carinulatus CPR., MS. 



Carpenter's notes on the single type specimen in the British 

 Museum are as follows : A long, narrow, rather pollicaroid shell, 

 the shape of longicymba. Girdle with very small, distinctly but 

 finely striated scales. Mucro at the anterior fourth. Jugum rather 



