eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 315 



Four specimens, 68-75 mm. Gluck Island. (C. M. Cat. No. 1886a; I. U. 

 Cat, No. 12165.) 



Ten specimens, 57-73 mm. Konawaruk. (C. M. Cat. No. 1887a-6; I. U. 

 Cat. No. 12166.) 



Six specimens, 53-74 mm. Warraputa. (C. M. Cat, No. 1888o-fe; I. U. Cat, 

 No. 12167.) 



One specimen, 79 mm. Tumatumari. (C. M. Cat. No. 1889.) 



Seventeen specimens, 65-85 mm. Rupununi. (C. M. Cat. No. 1890a-d; 

 I. U. Cat, No. 12168.) 



Head 4.3-5; depth 4.5; D. 10; A. 35 or 36; scales 8-65 or 66-5. Eye 1 in 

 snout, 3 in head, 1 in interorbital in the largest; .75, 2.5, and 1 respectively in the 

 smallest. 



Slender, compressed, resembling Creatochanes; ventral arch slightly greater 

 than the dorsal; preventral area rounded, predorsal area similar, neither with a 

 distinct median series of scales. 



Occipital crest short, about 9 in the distance from its base to the dorsal; 

 fontanels broad, ohe parietal fontanel twice as long as the frontal, which extends 

 to above the middle of the eye; interorbital convex; jaws equal, the mouth ter- 

 minal, short, the maxillary meeting the premaxillary at an angle; cheeks narrow, 

 entirely covered by the suborbitals. Premaxillary with five pluricuspid teeth in 

 the inner series, a single much narrower tooth in front of the space between the 

 first and second tooth; maxillary with one or two teeth similar to those of the 

 inner teeth of the premaxillary; seven similar graduate teeth on each side of the 

 lower jaw. 



Gill-rakers short, slender, 5 + 10. 



Scales thin, adherent, regularly imbricate, with few radiating striae. Anal and 

 caudal naked; lateral line slightly decurved; axillary scale well-developed. 



Origin of dorsal equidistant from base of middle caudal rays and middle or 

 anterior margin of eye, its height less than one-fifth of the length; adipose fin 

 small; caudal forked, its lobes about 5 in the length; anal very long, emarginate in 

 front, its base about 3 in the length; ventrals scarcely reaching anal. Pectorals 

 broad, placed low, their bases nearly horizontal, their tips not quite reaching the 

 ventrals. 



Iridescent, a rusty spot on upper part of caudal peduncle; upper caudal lobe 

 dark, darkest towards the base of the middle rays; a silvery lateral band; a black 

 dorsal line. 



