1886.] NATURAL SCIENCES OF PHILADELPHIA. 261 



Head 3^ to 3^ ; depth S^ ; scales 5-49-9 ; D. IX-10; A. III-T. 



Body elongate, elliptical, not mucli compressed; back little 

 elevated ; profile evenly convex ; top of* head little convex ; 

 mouth rather small, end of maxillar}' reaching slightly past 

 vertical from front of orbit ; length of maxillary 3^ in length of 

 head, its exposed portion nearly triangular and about i length 

 of head, its greatest width ^ its greatest length. Preorbital 

 and preopercle entire. Snout not much pointed, conical ; cheeks 

 each with three rows of scales ; seven gill-rakers below the angle. 

 E3'^e 3^ in head, snout 3;^ in head ; interorbital area 3| in head. 

 Dorsal spines all weak and flexible. Second and third dorsal 

 spines subequal, 1^ in length of head. Base of anal 2 in length 

 of head, spines small, the second the stronger, its length 4^ in 

 length of head, about equal in length to third spine or slightly 

 the shorter. Least depth of caudal peduncle 3 in length of head. 



Tips of pectoral fins reaching vent, their length about 3| in 

 length of body. Ventrals 1^ in head, their tips reaching | dis- 

 tance to vent. Premaxillary grooves long, linear and free from 

 scales. 



Color greenish above, with bluish reflections, silvery below ; 

 snout blackish ; tips of spinous dorsal black ; pectorals pale, 

 dusky in axil. Yentrals and anal pale. Caudal reddish. 



This species has been sometimes confounded with Gerres 

 gracilis. It can easily be distinguished from the latter b}' its 

 more elongate form and its comparatively small anal spines. 



There seems to be no room for doubt of the identity of G. 

 jonesi \<[ii\i G. pseudogula. 



4. Gerres gracilis. 



Biapterus gracilis Gill, Pioc, Acad. Nat. Sci. Phila., 1863, 246 (Cape 

 San Lucas). 



Gerres gracilis Jordan & Gilbert, Proc. U. S. Nat. Mus., 1881, 374 

 (Guaymas); Jordon & Gilbert, Bull. U. S. Fish Comm., 1881, 329 

 (Guaymas ; Mazatlan ; Panama); Jordan & Gilbert, Bull. U. S. Fish 

 Comm., 1882, 108 (Mazatlan; Panama); Jordan, Proc. U. S. Nat. 

 Mus., 1884, 130 (Key West); Jordan, Cat. Fish. N. A., 1885, 95. 



Oerres aprion Giinther, Cat. Fish. Brit. Mus., i, 358, 1859 (San Do- 

 mingo ; Jamaica ; West Indies ; South America); Giinther, Cat. Fish. 

 Brit. Mus., iv, 255, 1863 (San Domingo ; Jamaica ; Bahia); Bean & 

 Dresel, Proc. U. S. Nat. Mus., 1884, 154 (Jamaica) (not of Cuv. & 

 Val.). 



