DEC. 28, 1916. FISHES OF PANAMA MEEK AND HILDEBRAND. 273 



first arch; lateral line incomplete, present on 10 to 16 scales; scales thin, 

 striate; dorsal fin small, its origin somewhat nearer base of caudal than 

 tip of snout; caudal fin naked, its lower lobe the longer; anal fin very- 

 long, its base greater than half the length of body; ventral fins minute, 

 scarcely longer than eye, reaching origin of anal; pectoral fins rather 

 long, overlapping ventrals, but not quite reaching the tips of the latter. 



Color translucent, silvery; sides with a dusky band, most distinct 

 posteriorly. Scales with chromatophores, which are also present on 

 the fins; chin and maxillary black; no caudal spot. 



The present collection contains 12 specimens of this species, ranging 

 in length from 35 to 57 mm. These were taken at various points in the 

 Rio Tuyra Basin. A comparatively rare species. 



We have for comparison a paratype of P. wilsoni Eigenmann, which 

 we find to be identical with the present species. It is noted that in the 

 original description of P. wilsoni the scales in the lateral series are given 

 as 34 or 35. However, we are able to count 42 in the paratype that is 

 at hand. 



Habitat: Rio Tuyra and Rio Atrato basins. 



19. Genus Compsura Eigenmann. 



Compsura Eigenmann, Memoir. Carnegie Mus., VII, 1916, 60 (type 



Compsura heterura Eigenmann). 



Minute fishes, with few teeth; multicuspid incisors, in a single series 

 in each jaw, 2 or 3 teeth on maxillary; second suborbital in contact 

 with the preopercle below and partly behind; lateral line incomplete; 



FIG. 1. DIAGRAM SHOWING THE PECULIAR SCALING AT BASE OF CAUDAL FIN 



OF THE MALE OF Compsura gorgoiut (Evermann & Goldsborough). 



scales thin, with a few radiating striae; the male with a peculiar lobe of 

 enlarged scales on lower half of base of caudal; origin of dorsal about 

 equidistant from snout and base of caudal; adipose fin well developed; 

 interhasmal spines of caudal peduncle not projecting; a conspicuous 

 caudal spot present. 



