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



it is with great hesitation that I describe it as a second species, attaching to it the name 

 of the discoverer of the genus. There are two points in which our specimen apparently 

 differs from the Cuban specimen. First, it possesses an enormously large first? dorsal 

 spine; but then this spine is but loosely articulated with the interneural, and it is quite 

 possible that it may have been lost, during or after the life of the fish, in Professor 

 Poey's specimen. Secondly, the original description in the Proceedings of the Phila- 

 delphia Academy mentions a postanal spine at the commencement of the anal fin, 

 which, however, is afterwards explained by Professor Poey to be hidden under the skin, 

 and therefore not apparent in his figure. Neither should I have taken any notice of 

 this spine in our specimen ; it is entirely covered by skin, and consists of coalesced and 

 flattened interhaemal elements, and cannot be properly called a spine. But in our speci- 

 men, a single oval scale slightly bent along the middle occupies the place at a short 

 distance behind the vent ; this scale is quite similar to the scales representing the ventral 

 fins, but single, and of about the same size. 



The specimen is a dry skin, 78 inches long, and in a good state of preserva- 

 tion; it was unknown to any of the fishermen at Port Louis, and the captor stated 

 that he had obtained it at a depth of 70 fathoms. 



D. 93. A. a: -I- 20. P. 12. 



The greatest depth of the body is below the first dorsal spine, and one-thirteenth of 

 the total length or even less; length of the head one-eighth of the total; orbit occupying 

 the middle of the depth of the head, a little nearer to the end of the snout than to the 

 end of the gill-cover, and one-fifth of the length of the head. Each jaw with a series 

 of small, flat, and triangular teeth, but the upper jaw is armed besides with three large 

 compressed fangs which stand inside the outer series of small teeth, and of which the 

 two posterior are placed more closely together, and are somewhat larger than the 

 anterior ; in the lower jaw the foremost pair is very little larger than the others. The 

 first dorsal spine is large, compressed, sword-shaped, finely ribbed, and in its mutilated 

 condition not much shorter than the head. The lower pectoral rays are twice as long 

 as the upper, and half as long as the head; vent somewhat in advance of the middle 

 of the total length. A large scale marks the commencement of the anal fin, the rays 

 of which begin to be free in the posterior third of its extent. Hind part of the tail 

 very slender; caudal fin deeply forked. Coloration in the present state of the specimen 

 uniform silvery. 



I have given on PI. XLIII. a view of the anterior part of the fish of the natural size, 

 an outline figure, reduced in size, of the entire fish, and separate views of the pair of 

 ventral scales {a) and of the single postanal scale (6). 



