CALLISTOCHITON. 275 



but the number in front is ordinarily from 10 to 12, behind from 

 -8 to 12. The tail valve is much depressed, as in C. gabbi. 



Carpenter described a large, fine specimen as 0. sarcophagus, but 

 upon examining Keeve's type he concluded that it was merely a well 

 developed antiquus. The type is in the British Museum. 



C. COPPINGERI Smith. PI. 59, fig. 36. 



Shell elongate, greenish-white, stained with a dark green color 

 along each side near the girdle, with a paler indistinct stripe on 

 each side of the central line, the apex of the valves being somewhat 

 livid. Central valves with a straight posterior margin, arched, with 

 only the faintest indication of a carina at the vertex. Lateral areas 

 somewhat raised, with two radiating rows of coarse transverse 

 rugae, of which the hinder or marginal are the largest. The surface 

 between them is finely granular. Central areas covered with a 

 more or less criss-cross granulation, the granules at the center being 

 very minute, and gradually increasing in size toward the sides, 

 where there is very little of the criss-cross arrangement seen at the 

 vertex, but rather a longitudinal disposition of them. The front 

 valve is minutely granulated and has about twenty fine radiating 

 ridges, here and there some of them bifurcating near the circum- 

 ference. Posterior valve rather large, concave behind the sub- 

 central mucro, in front of which the surface is sculptured in the same 

 manner as the front of the central valves, as is usual with most, if 

 not all Chitons. The posterior half is finely grained and sparsely 

 covered with pustules of different shapes and sizes. The coarsest being 

 near the margin and the smallest near the center. The insertional 

 plates are thin, with twelve slits in the last, at unequal distances, 

 eleven in the front one, and one on each side of the intermediate 

 valves. The interior is pale bluish, the latter valves having an olive- 

 brown stain radiating from the vertex behind on each side, and the 

 >two terminal valves have marks of the same color near the middle. 



The girdle is covered with alternately pinkish and dark grayish 

 patches of fine oval compressed imbricating scales, of which those 

 toward the outer margin are much smaller than those near the 

 valves. 



Length without girdle 21 millim. ; diameter of fifth central plate 

 8 mill. (Smith.) 



Port Jackson, Australia (Coppinger.) 



Chiton ( Callistochiton) copping eri E. A. SMITH, Rep. Zool. Coll. 

 H. M. S. ' Alert/ p. 80, t. 6, f. E (1884.) 



