24 



The lines of striation are worn away considerably, indicating, perhaps, that it was an old fish. 

 It was when entire, about eight inches long, and it is two inches in diameter from the anterior 

 edo-es of the dorsal and anal fins. The lithographic delineation gives a suflficiently full exhibition 

 of "the character of this specimen, which appears to be of the same species, or very near the 

 species, last described." 



The type, and figured specimens of Jackson, together with the specimens belonging to this 

 Survey, form a series from which it is now possible to form a fairly correct idea of the general 

 shape of the species, and of many details of its structure. 



Our knowledge of the head must, for the present, remain deficient, as in all the specimens 

 that part is obscure, and provides the least reliable information, principally on account of the 

 effects of crushing, which are more apparent here than in other parts of the body. Some of the 

 specimens furnish an approximately true outhne of the fish, with the exact position of the fins, 

 but without much detail; from others we obtain particulars of structure, and the minutiae of 

 scale ornamentation. 



From a study of all available material this species seems to possess stable characters in 

 general, but to vary slightly as regards the ornamentation of the scales, a variation which appears 

 to be quite independent of the age or size of the individual. It belongs to the genus Elonichthys. 



Elonichthys brovmi (Jackson) may be described as follows: — 



A species of moderately large size, reaching a length of 37'5 cm. (about 15 inches). Maximum 

 depth of the trunk, slightly in advance of the pelvic fins, contained about three and three- 

 quarters times in the total length. Length of head, including the opercular apparatus, about 

 one-fifth of the total length. Fins rather large. Pectoral fin powerful, spreading, with a rather 

 restricted base; rays articulated, except the first two or three proximally. Pelvic fins, small 

 in comparison with the other fins, about midway between the pectoral and anal fins, in advance 

 of the mid-length of the trunk. Anal fin, large, triangular, with a broad base, reaching poster- 

 iorly close to the tail. Dorsal fin, similar in shape to the anal but not quite so large, the centre 

 of its base nearly above the anterior end of the base of the anal. Caudal fin large, the body 

 prolongation of the upper lobe robust, extended, the lower lobe well developed. Fulcra in all 

 the fins conspicuous. External bones of the head ornamented with definite ridges of varying 

 length, straight or slightly tortuous and having a general longitudinal direction, replaced at 

 times by tubercles. Flank scales, near the head, ornamented with numerous longitudinal 

 striffi, and a serrated posterior border. Usually, in passing backward on the trunk, these strise 

 gradually disappear, being replaced by a few punctuations, the surface of the scales becoming 

 smoother and the serrations of the posterior border fewer in number, until in the upper lobe 

 of the tail both punctuations and serrations are lost and the scales are quite smooth. It is 

 found, however, that the striations of the scales persist in a variable degree, in different specimens, 

 in the posterior half of the trunk, and in some, even the caudal scales retain a number of the 

 strife. Enlarged, longitudinally striated, imbricating dorsal ridge scales extend in a row from 

 near the head to the dorsal fin, and from the latter to the extremity of the tail, on the upper 

 lobe of which they are of modified shape and gradually diminishing size. Between the anal 



