38 THE VOYAGE OF H.M.S. CHALLENGER. 



of tlie head; the latter is two-fifths of the length of the trunk, and one-seventh of the 

 total. The lateral teeth are comparatively stronger and fewer in number than in 

 Lejndojms caudatus. The terminal portion of the tail becomes so slender that its entire 

 depth is occupied by the mucous canal of the lateral line, which is very wide. Caudal 

 fin very small. The anterior anal rays are not free, but hidden below the skin. 

 Uniform silvery. 



Habitat. — Ofi" Inosima, Japan, Station 232 ; depth, 345 fathoms. One specimen, 

 24 inches long. 



The above diagnosis requires scarcely any addition. The two pairs of large teeth 

 which occupy the front of the upper jaw in Lepidopus caudatus are present also in this 

 species, but happen to be broken ofi" near the base in the present specimen. None of the 

 teeth show a trace of being barbed near the apex. Gill-rakers minute and remote from 

 each other. The inside of the mouth and pharynx is black, indicating, in conjunction 

 with the wide lateral line, delicate structure of the skin, fin-rays and membranes, the 

 bathybial habits of the fish. On the other hand, its eye is comparatively smaller than in 

 Lepidopus caudatus, being contained seven and a half times in ,the length of the head, 

 and three and a half times in that of the snout. 



Lepidopus elongatus. 



Lepidopus elongahis, Clarke, Trans. New Zeal. Inst., vol. xi., 1879, p. 294, pi. xiv. 

 Benthodesmus elongatus, Goode and Bean, Proc. U.S. Nat. Mus., vol. iv., 1882, js. 379. 



D. 154-155. A. 25 (Clarke). 100 (G. and B.). 



This fish is so closely allied to Lepidopus tenuis that I should have referred it to 

 that species, but for the circumstance that both the descriptions agree in assigning to 

 it twenty-eight or twenty-nine more dorsal rays than are found in the Japanese 

 specimen. Also the dermal elements of the anal fin seem to be more numerous in 

 Lepidopus elongatus than in Lepidopus tenuis. Clarke represents the caudal fin as 

 distinctly forked, and so it may have been in the specimen of Lepidopus tenuis, in 

 which this fin is much mutilated. He also counted of the anal rays those only which 

 were connected by membrane, and it is quite possible that at an earlier age a similar 

 connection existed between the posterior rays in Lepidopus tenuis. 



The discoverer of this fish found eight or ten specimens washed ashore on the 

 Hokitika Beach on October 12, 1874; the largest was 27-g inches long. The example 

 described by the North American ichthyologists was taken from the stomach of a Halibut 

 caught in 80 fathoms on the Grand Bank of Newfoundland. 



