80 [SCHNOCHITON, 



I. PUSILLUS Sowerby. PI. 8, figs. 69, TO. 



Shell small, obovate, whitish ; back elevated : intermediate valves 

 narrow, very minutely punetulate : lateral areas somewhat distinct ; 

 posterior valve larger, the apex central, inclined backward. (Sowb.) 



Length 6i, breadth lM mill. 



Hirnminnio, J'fi'ii, on a coral reef in 17 fins., miles from shore. 



C. ;>M.</////X Sows., P. Z. S. 1832, p. 57 ; Conch. Illustr. f. 31. 

 RKI.VE, Conch. Icon. f. 189. 



( 'arpenter's notes on the two specimens in the Cumingian collec- 

 tion are as follows: Length 5J, breadth 2-1 mill.; divergence 90, 

 nearly semicircular. Small, whitish-ashen, long, arched. No 

 jugum or jugal area. Lateral areas slightly swollen ; granulated, 

 but no other pattern. Mucro rather elevated, posterior slope very 

 concave. Posterior valve with 11, median 1, anterior 10 .-lit.-. 

 Teeth sharp, long and very thin; eaves conspicuous, not spongv. 

 Sinus deep, broad, flat, not channelled. The shell might pass in 

 sculpture for a young punctulatissimus ; in shape and size for Lep- 

 tockiton cancellatus ; but as far as I can see the girdle scales, they 

 are very minute and like Trachydermon, but they have mostly per- 

 ished, and the specimens have been rather smashed and are in bad 

 condition. 



I. 1:1 I:I:K Limit'. PI. 7, figs, 50-56. 



Shell oblong, elevated, solid, the back roundly subangular, lat- 

 eral slopes somewhat convex ; surface apparently smooth except 

 for well-marked grooves or wrinkles, indicating growth-periods, 

 lender the microscope, however, an excessively fine reticulation is 

 visible. The color is light buff, marbled all over with orange-red 

 in various patterns, or entirely suffused with reddish ; usually hav- 

 ing a red dorsal stripe bordered on each side with buff. 



The anterior valve is twice as wide as long, crescentic rather 

 than half-round. The intermediate valves are slightly beaked, 

 their lateral areas slightly raised and having stronger concentric 

 wrinkles than the central areas. Posterior valve having a rather 

 elevated but obtuse median umbo. 



The interior is briyht pink. The sutural plates are wide, large ; 

 tlirjnyil *in us is deep, narrow and anf/nfur. The insertion plate of 

 the anterior valve has 8 to 11 slits; intermediate valves normally 1 

 -lit: posterior Yalve 7 to 11 slits. The insertion plates are sharp 

 and smooth. 



