DEC. 28, 1916. FISHES OF PANAMA MEEK AND HILDEBRAND. 277 



21. Genus Gephyrocharax Eigenmann. 



Gephyrocharax Eigenmann, Indiana Univ. Studies, No. 16, 1912, 23 



(type Gephyrocharax choccensis 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., 1912, 68 (Rio Frijoles, Panama Canal Zone). 

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



1914, 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 



