Dec. 28, 1916. Fishes of Panama — Meek and Hildebrand. 277 



21. Genus Gephyrocharax Eigenmann. 



Gephyrocharax Eigenmann, Indiana Univ. Studies, No. 16, 191 2, 23 



(type Gephyrocharax chocoensis Eigenmann). 



Body elongate, compressed; premaxillary teeth in 2 series, the 

 inner with 8 to 10 teeth; second suborbital covering the entire cheek; 

 lateral line complete; dorsal fin inserted posteriorly, its origin nearer 

 caudal than eye, notably behind origin of anal; adipose fin present; the 

 lower fulcra of caudal free, forming a peculiar spur in the male; pectorals 

 long, overlapping the ventrals. 



KEY TO THE SPECIES. 



a. The outer rays of caudal fin black; no distinct shoulder spot. 



atricaudata, p. 277. 



aa. The outer rays of caudal without black; a distinct shoulder spot 



present. intermedius sp. nov.,p. 278. 



27. Gephyrocharax atricaudata (Meek & Hildebrand). 

 Deuterodon atricaudata Meek & Hildebrand, Field Mus. Nat. Hist. 



Pub., Zool. Ser., 191 2, 68 (Rio Frijoles, Panama Canal Zone). 

 Gephyrocharax atricaudata Eigenmann, Indiana Univ. Studies, No. 20, 



19 1 4, 41 (Panama Canal Zone). 



Head 3.7 to 4.5; depth 2.8 to 3.8; D. 9 or 10; A. 26 to 33; scales 37 

 to 43. 



Body elongate, rather strongly compressed; dorsal profile anteriorly 

 straight or slightly concave; ventral outline strongly convex; abdomen 

 round in advance of ventrals, keeled from ventrals to vent; head com- 

 pressed; snout blunt, 3.4 to 4.75 in head; eye 2.6 to 3.44; interorbital 

 2.4 to 3.1; mouth small, very oblique; the lower jaw a little in advance 

 of the upper; maxillary reaching slightly past anterior margin of eye; 

 second suborbital broad, its lower posterior angle rounded; premaxillary 

 teeth in 2 series, the outer series consisting of 8 teeth, each with 3 to 5 

 cusps; the inner series with 8 broad teeth, each with 5 cusps, the middle 

 cusp much enlarged; maxillary with 2 small teeth; lower jaw with 8 

 large teeth and abruptly smaller ones at sides; gill-rakers short, about 

 8 on lower limb of first arch; lateral line complete, curved downward 

 anteriorly; scales striate, 20 to 23 in median series in advance of dorsal; 

 6 complete rows between lateral line and base of dorsal; the rows below 

 lateral line abruptly bent downward and backward toward anal; 5 

 scales in vertical series between lateral line and base of anterior rays of 

 anal; the last scales on lower lobe of caudal much enlarged in males, 

 with a hollow space or pocket underneath, its upper edge attached to 



