EIGENMANN: the freshwater fishes of BRITISH GUIANA 351 



Type, 54 mm. Warraputa. (Carnegie Museum Catalog of Fishes No. 1013.) 



Cotypes, one hundred and seventy-six specimens. Rockstone. (C. M. Cat. 

 No. 1014a-2; I. U. Cat. No. 11717.) 



Cotypes, two specimens, 45-52 mm. Crab Falls. (C. M. Cat. No. 1015; 

 I. U. Cat. No. 11718.) 



Cotypes, two specimens, 50-55 mm. Warraputa. (C. M. Cat. No. 1016; 

 I. U. Cat. No. 11719.) 



Cotypes, thirty-four sjiecimens, 43-55 mm. Tumatumari. (C. M. Cat. No. 

 1017«-j; I. U. Cat. No. 11720.) 



Allied to A. multidens, but without a caudal spot. 



Head 4; depth 2.6-3; D. 10 or 11; A. 25-27; scales 5-34 or 35 (rarely 36)-4; 

 eye 2.33; interorbital 3. 



Compressed, subrhomboidal ; ventral profile regularly arched; dorsal profile 

 with an angle at the origin of the dorsal, slightly depressed over the eye; preventral 

 area rounded, tending to flatfish, with a median series of scales, sometimes irregular 

 in the middle; postventral area narrowly rounded; predorsal area rounded, with a 

 median series of nine scales. 



Occipital process about 4 in the distance from its base to the dorsal, bordered 

 by three scales on the sides; interorbital flat, with marginal grooves; frontal fontanel 

 shorter, triangular; second suborbital covering the entire cheek, with the exception 

 of a triangiflar area below the junction between the first and second suborbitals; 

 maxillary much shorter than the eye, 3 in the head; four or five teeth in the first 

 row of the premaxillary, if five, the third very slightly out of line with the others; 

 five graduated teeth in the second row, their denticles arranged in a slight crescent; 

 four to seven teeth in the maxillary; mandible with four large teeth, and abruptly 

 smaller ones on the sides. 



Scales everywhere regularly imbricate, no omitted or interpolated scales; 

 each scale of the side with from two to eight diverging striae; anal sheath of very few 

 scales in a single series along the base of the anterior rays; a few scales on the base 

 of the caudal lobes. 



Ventrals slightly nearer to the snout than to the dorsal ; origin of the dorsal in 

 advance of the middle, its highest ray 3.25 in the length; anal deeply emarginate, 

 the second and eleventh rays reaching the base of the eighteenth; ventrals reach- 

 ing anal, pectorals slightly beyond ventrals. 



Opercle dusky; a dark vertical l)and crossing the third to the sixth scales behind 

 tlie head; a dusky streak below origin of dorsal; sides behind this profusely dotted; 

 margins of scales of the sides of the abdomen with a few color-cells; very few cells 



