84 PROCEEDINGS OF THE ACADEMY OP 



third of the base; the straight portion equals a third of the total length. The 

 second dorsal spine is very long ; the third little longer than the base of 

 its fin. The caudal lobes diverge at nearly a right angle ; the length of 

 the lower nearly equals three-tenths of the total. The pectoral fin equals a 

 quarter, and the ventral two-fifths of the total length. 



D. VIII. I. 22. A. II. I. 18. 



The color is silvery, punctulated, with black near the edge of the back, and 

 withablack baronthehead above the eye, parallel with the forehead. The fila- 

 mentous dorsal spines and the elongated dorsal and anal rays are blackish. 

 The ventrals have the terminal half blackish, and the other whitish, with 

 a median black band. 



This species is distinguished by its proportions, oblique profile, lateral line 

 and color. It may be further remarked that the branch of the lateral line ascend- 

 ing from the scapula divides into two branches, diverging at less than a right 

 angle ; the anterior branch appears to be a groove. 



I have dedicated this species to my excellent friend, Mr. Brevoort, who has 

 paid much attention to the group of fishes of which the present is a member. 



Genus HALATRACTUS Gill. 



Halatractus dorsalis Gill. 

 The greatest height equals a quarter of the length to the end of the median 

 caudal rays. The head enters more than three times and a half (-28) in that 

 length. The diameter of the eye equals a quarter of the head's length, and is 

 shorter than the length of the snout (=-09). The median caudal rays forms 

 an eleventh of the length, and the longest equal a fifth. The pectoral fin 

 nearly equals a seventh ('13), and the ventral nearly a sixth ( - 16) of the 

 length. 



D. VII. I. 37. A. II. + 1. 21. P. 2. 19. 



The color is brassy, purplish on the back, and with ten indistinct darker 

 bands, twice as wide as their intervals ; the second between the second and 

 fifth dorsal spines. The dorsal and anal fins are nearly black; the anterior 

 angle of the latter lighter. The ventrals dusky, with the rays externally 

 white. 



This species is most nearly related to Halatractus zonatus Gill, and H. caro- 

 liniensis, Gill, of the Eastern American coast; but readily distinguished by the 

 color and proportions. 



Genus TRACHYNOTUS Lacepede. 

 Trachynotus Carolincs Gill. 



This species is extremely variable, as are also the other well-known repre- 

 sentatives of the genus. In extreme youth, the jaws and palate are dentigerous, 

 and the angle of the preoperculum armed with three radiating spines ! while the 

 spinous dorsal and anal are elevated, and the angles of the soft fins scarcely 

 produced. Later, the preopercular spines become obsolete ; then the palatal 

 teeth are lost ; the spines of the fins meanwhile become abbreviated, and , 

 finally, in old age, the teeth have entirely dropped out, the spines become 

 much shortened, and the angle of the fins considerably produced. Half- 

 grown specimens answer to the genus Doliodon, of Girard ; nearly mature 

 ones, with teeth in the jaws, Trachynotus, C.V. ; and old ones, without teeth, to 

 Bothrolxmus, Holbrook. Relying on the correctness of my predecessors, who 

 had certainly the opportunities, if they had availed themselves of them, to 

 avoid such errors, I adopted the several genera proposed by Holbrook and 

 Girard in my Catalogue of the Fishes of the Eastern Coast; Gunther first 

 corrected the synonymy as lately given, and, under the other North American 

 species, has brought together nine of Cuvier's species and two of other 

 authors ! 



[Mar. 



