20 Annals of the Carnegie Museum. 



Cotypes, 14 specimens, 46-73 mm. Sandbank in Potaro at Tukeit. 

 (C. M. Cat. No. 1027, a-e ; I. U. Cat. No. 11 726.) 



Head 3-6; depth 2.3-2.6; D. 11 ; A. 25-26, rarely 27; scales 

 6-34 or 35-5 (rarely 4). Eye 2.7; 2 in the head without the opercle ; 

 interorbital 3-3.5 in the head. 



Compressed, subrhomboidal, with heavy head and slender caudal 

 peduncle. Dorsal profile slightly depressed over the eye, rising with 

 a gentle curve to the origin of the dorsal, abruptly descending to 

 the end of the dorsal and then with a more gentle slope to the 

 caudal peduncle. Ventral profile more regularly arched. Preventral 

 region broadly rounded^ postventral area more narrowly rounded"; 

 predorsal area keeled, with a median series of eight scales. 



Occipital crest exceptionally narrow at the base ; about one-fourth of 

 the distance from its base to the dorsal bordered by three scales on 

 the sides ; skull narrow, slightly convex, smooth. Fontanels very 

 narrow and long, the frontal fontanel as long as the parietal. Second 

 suborbital leaving but a very narrow naked area. Maxillary but little 

 longer than snout, 3.3 in the head. Premaxillary with two or three 

 teeth in the front series, five teeth in the second series, their denticles 

 in a straight line ; two teeth on the maxillary ; lower jaw with eight 

 teeth arranged in a crescent (four on each side), smaller teeth on the 

 sides. 



Gill rakers 5 -f-.io. 



Scales very regularly imbricate, without interpolated or omitted rows. 

 Each scale with several slightly diverging striae ; anal sheath of a single 

 row of scales along the base of the anterior rays ; caudal naked. 



Origin of dorsal nearer snout than caudal, 3.4 in the length; anal 

 emarginate, its origin about equidistant from snout with the eighth 

 dorsal ray ; ventrals reaching anal, their origin a little in advance of 

 that of the dorsal. Pectorals reaching beyond origin of ventrals. 



A conspicuous bullet-shaped humeral spot, the blunt end forward, a 

 faint dark streak extending down from it ; a diffuse caudal spot occupy- 

 ing the entire width of the end of the caudal peduncle. 



Dorsal line dark ; sides profusely covered with pigment cells disap- 

 pearing on the belly ; cheeks and opercles dotted ; fins dotted ; upper 

 and lower margin of caudal dark. Straw-colored in life, bases of 

 dorsal, anal, and caudal lobes ochreous. 



