Dec. 28, 1916. FisHes of PANAMA— MEEK AND HILDEBRAND. 295 
Body elongate, compressed; profile slightly concave over eyes, 
slightly rounded in region of dorsal; head rather small; snout pointed, 
3.5 to 4.3 in head; eye 3 to 4.6; interorbital 2.35 to 3.5; mouth moderate; 
upper jaw strongly projecting; maxillary scarcely reaching middle of 
eye, 2.05 to 2.3 in head; premaxillary teeth laterally in only 2 series, 
anteriorly in 4 series, the third series consisting of only 2 teeth; the fourth 
or transverse series situated just in front of the teeth in lower jaw, 
composed of 3 or 4 teeth; the series on outer edge of maxillary very small, 
only 9 or 10 in number; those in lower jaw very large and strong, usually 
8, rarely 7 and occasionally 9g in first series; gill-rakers rather small, 
about 15 on lower limb of first arch; lateral line complete, curved down- 
ward; scales moderate, regularly placed, 18 to 21 vertical rows crossing 
back between dorsal and adipose, 4 or 5 longitudinal rows between 
lateral line and base of pectoral; dorsal fin inserted slightly nearer base 
of caudal than tip of snout; caudal fin forked, the lower lobe the longer; 
anal fin long, its base much longer than head, inserted slightly behind 
base of last ray of dorsal; ventral fins inserted midway between base of 
pectoral and origin of anal or slightly nearer the latter; pectoral fins 
inserted under margin of opercle, usually reaching nearly to base of 
ventrals. 
Color steel blue above, silvery below; a black bar on shoulder behind 
-margin of opercle; sides otherwise perfectly plain in our largest speci- 
mens. The smaller ones with indistinct blackish vertical bars and a 
large caudal spot. Young of 100 mm. and less in length with a dark 
lateral band. Fins unmarked at all ages. 
This species is represented by 62 specimens, ranging from 45 to 
365 mm. in length. It was taken in the Rio Chorrera at Chorrera, Rio 
Juan Diaz, a small stream near Panama, and in the Rio Bayano and Rio 
Tuyra basins, 
Habitat: Pacific slope of Panama. 
41. Brycon chagrensis (Kner). 
Chalcinopsts chagrensis Kner, Sitzungsb. K. Bayer. Ak. Wiss. Manchen., 
1863, 223; Kner & Steindachner, Abhandl. K. Bayer. Ak. Wiss. 
Miinchen., 1864, 42, Pl. V, fig. 3 (Rio Chagres); Ginther, Cat. 
Fish. Brit. Mus., V, 1864, 338; Vaillant, Bull. Mus. d’Hist. Nat., 
1897, 22 (Rio Chagres). 
Brycon striatulus (in part) Jordan & Evermann, Bull. U. S. Nat. Mus., 
XLVII, 1896, 337; Eigenmann & Ogle, Proc. U. S. Nat. Mus., 
XXXIII, 1907, 30 (Aspinwal, now Colon); Evermann & Golds- 
borough, Proc. Biol. Soc. Wash., XXIII, r910, 4 (Panama Canal 
Zone). 
