Dec. 28,1916. FisHes or PANAMA— MEEK AND HILDEBRAND. 277 
21. Genus Gephyrocharax Eigenmann. 
Gephyrocharax Eigenmann, Indiana Univ. Studies, No. 16, 1912, 23 
(type Gephyrocharax chocensis 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. Thetater save Ge ee no distinct shoulder spot. 
atricaudata, p. 277. 
aa. Phhe:ciuter seiveick taauiel iihinell eile, a distinct shoulder spot 
present. intermedius sp. nov., p. 278. 
27. Gephyrocharax atricaudata (Meek & Hildebrand). 
Deuterodon atricaudata Meek & Hildebrand, Field. Mus. Nat. Hist. 
Pub., Zodél. 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 
