DEC. 28, 1916. FISHES OF PANAMA MEEK AND HILDEBRAND. 283 



KEY TO THE SPECIES. 



a. Scales regularly placed, in 35 to 41 oblique series from upper 

 angle of gill-opening to base of caudal; n to 13 scales in advance 

 of dorsal; 10 or n between dorsal and adipose; 7 complete, 

 longitudinal rows between lateral line and base of dorsal. Color 

 silvery, with a plumbeous lateral band. Breeding males with- 

 out tubercles on head and margin of scales; fins nearly smooth. 



emperador, p. 283. 



aa. Scales more or less irregularly placed, in 40 to 48 oblique series 

 from upper angle of gill-opening to base of caudal; 12 to 15 

 scales in advance of dorsal; 12 to 14 between dorsal and adipose; 

 8 complete longitudinal rows between lateral line and base of 

 dorsal. Color dark silvery, lateral band very dark posteriorly. 

 Breeding males with small tubercles on head and margin of 

 scales; the fins with barbs, very rough to the touch. 



cascajalensis sp. nov., p. 284. 



31. Bryconamericus emperador (Eigenmann & Ogle). 



Astyanax emperador Eigenmann & Ogle, Proc. U. S. Nat. Mus., XXXIII, 



1907, 26 (Empire, Panama Canal Zone). 

 Bryconamericus emperador Eigenmann, Indiana Univ. Studies, No. 18, 



Pt. II, 1913, ii. 



Head 3.05 to 4; depth 2. 5 to 3; D. loom; A. 24 to 29; scales 35 to 41. 



Body rather deep, compressed, the back elevated; head small; 

 snout conical, 3.8 to 4.8 in head; eye 2.5 to 2.85; interorbital 2.75 to 3; 

 mouth small; jaws subequal; maxillary reaching anterior margin of 

 pupil, slightly longer than snout; premaxillary teeth in 2 series, the 

 outer series irregular, with 10 teeth, the inner series regular with 8 to 



10 teeth; maxillary with 2 small teeth near its juncture with the pre- 

 maxillary; lower jaw with 8 large teeth anteriorly and abruptly smaller 

 ones at sides; gill-rakers short, about 12 on lower limb of first arch; 

 lateral line complete, moderately decurved; scales moderate, striate, 



11 to 13 in advance of dorsal, 10 or n between dorsal and adipose, 7 

 or 8 longitudinal rows between anterior dorsal rays and lateral line; 

 dorsal fin inserted midway between tip of snout and base of caudal; 

 adipose fin about one-third as far from base of upper caudal ray as 

 from base of last dorsal ray; caudal fin forked, the lower lobe the longer; 

 anal fin rather long, its origin a little behind base of last dorsal ray, about 

 midway between base of pectorals and base of caudal; ventral fins reach- 

 ing to or slightly past vent, inserted midway between tip of snout 

 and base of last anal ray; pectoral fins usually reaching to base of ven- 

 trals, inserted midway between tip of lower jaw and base of ventrals. 



