64 G- O. Sars. 



(fig. 6 a) it is almost median. On the whole, the posterior 

 part of the shell in the male (fig. 6 b) appears broader and 

 more expanded than in the female (fig. 6 a), and the ante- 

 rior extremity more produced. Seen from above (fig. 6 c), 

 the shell in both sexes appears very narrow oblong, with 

 the anterior extremity somewhat more pointed than the 

 posterior. 



The valves are nearly equal, and rather thin, are 

 semipellucid, and clothed at each extremity with delicate hairs. 

 The inner duplicatures are rather broad, especially the ante- 

 rior ones, and their defining edges may be fairly well traced 

 through the shell. 



The surface of the shell appears quite smooth and 

 polished, though exhibiting, when examined under a strong 

 magnifier, an extremely delicate reticulation. 



The colour of the shell in living specimens is trans- 

 parent whitish, permitting several of the inner organs to be 

 fairly well traced through it. 



The eye is very small, and, it would seem, devoid of 

 the usual dark pigment, being on that account rather difficult 

 to trace. 



The structure of the several appendages seems exactly 

 to agree with that described by Mr. Vävra in the typical 

 species, C. Kingsleyl 



The caudal rami (fig. 6 d), as in that species, are rather 

 narrow, sublinear, and lack all trace of the usual dorsal 

 bristle. They are, however, in the present species straighter, 

 and each of the terminal claws has beyond the middle a 

 very conspicuous secondary denticle, not found in the typical 

 species. 



In the male (fig. 6 b — c) the very large «mucous 

 glands», or more correctly the «zenckerian organs» are 



