84 ISCHNOCHITON. 



having about 18 radiating, irregular series of pustules. Posterior 

 valve having the mucro subcentral, much depressed. 



iDterior whitish, but showing through the white layer the tints of 

 the exterior. Anterior valve having 11, median valves 1-1, poste- 

 rior valve 7 slits ; teeth short. Sinus with a concave, smooth lamina, 

 separated from the sutural laminae by a notch at each side (fig. 61.) 



Girdle alternately gray -blue and whitish, densely clothed with 

 scales, unequally but generally rather deeply striated, and measuring 

 2 to '25 mill, in width (pi. 17, fig. 60). 



Gills slightly over f the length of the foot. 



Length 11, breadth 6 mill. ; divergence 100 to 110. 



Hong Kong, China. 



This types of the species (Mus. Smiths. Inst. 24117) are before 

 me. The shell closely resembles J. cultratus in general characters, 

 sharing with that species its general plan of sculpture, depressed 

 mucro, etc. But it differs in the partial or total absence of ribs at 

 the dorsal ridge ; in the concave lamina across the sinus; in the 

 fewer pustules, and the smaller girdle-scales; but this last feature 

 may be partly due to the fact that the specimens are much smaller 

 than those of cultratus. The sculpture upon the ridge of the second 

 valve is divergent, as in the other species of Lepidozona. 



I. CRATICULATUS Gould. PI. 17, figs. 62, 63. 



See p. 130, vol. xiv. 



Shell elevated and carinated, the side-slopes slightly convex. 

 Color light olive-gray, with rather small dark blue-green spots, 

 mainly visible on the central areas and along the sutural margins. 



Median valves squared. Lateral areas a trifle raised, sculptured 

 with 8-10 low radial rib lets bearing elevated rounded pustules; the 

 riblets fewer in young shells ; posterior row of pustules dentating 

 the sutures. Central areas having 18-22 narrow longitudinal 

 elevated threads, divergent on the ridge of each valve, their interstices 

 minutely latticed. Anterior valve having about 50 pustuliferous 

 riblets. Posterior valve elevated, high at the front margin, the 

 the mucro central and inconspicuous. 



Interior bluish or greenish-white, each intermediate valve having 

 a pair of wide posterior rays of olive-green, and a small patch of the 

 same color at the bases of the sutural lamince. Anterior valve having 

 10, median valves 1-1, posterior valve 11 slits; the teeth unequal, 

 and in the head valve distinctly notched or nicked at the edges and 



