Dec. 28, 1916. FisHes or PANAMA— MEEK AND HILDEBRAND. 287 
34. Hyphessobrycon panamensis Durbin. 
Hyphessobrycon panamensis Durbin, in Eigenmann, Bull. Mus. Comp. 
Zool., LII, 1908, 1or (Rio Boqueron, Atlantic slope, Panama). 
Hemigrammus minutus Meek & Hildebrand, Field Mus. Nat. Hist. 
Pub., Zodl. Ser., X, 1912, 67 (Agua Clara, Panama). 
Head 3.43 to 3.8; depth 2.4 to 2.85; D. 11; A. 22 to 25; scales 7-32 
to 36-6. 
Body short, compressed; profile straight over eyes, elevated from 
nape to dorsal; head short; snout blunt, 3.15 to 4.8 in head; eye 2 to 
2.65; interorbital 3 to 4.4; mouth rather small; jaws subequal; maxillary 
reaching anterior margin of pupil; premaxillary teeth in 2 series, the 
first series with 6 tricuspid teeth; the inner series with 10 teeth, each with 
3 or 4 cusps, one of the cusps considerably enlarged; maxillary with 3 
small teeth on the upper anterior angle; teeth in lower jaw in a single 
series, 8 large ones anteriorly, similar to the second series of premaxillary 
teeth but larger, and abruptly smaller ones at sides; gill-rakers short, 
about 10 on lower limb of first arch; lateral line present on 8 to 13 scales; 
scales thin, striate, 10 to 12 in advance of dorsal, 7 to 9 between dorsal 
and adipose, 12 longitudinal rows between base of dorsal and base of 
ventral; origin of dorsal midway between tip of snout and base of caudal; 
adipose fin well developed, over last rays of anal; caudal fin naked, the 
lobes of about equal length; anal fin slightly emarginate, its origin under 
last ray of dorsal; ventral fins reaching past origin of anal, inserted 
midway between tip of snout and base of last anal ray; pectoral fins 
reaching past base of ventrals, a little shorter than head. 
Color silvery ; sides with a dark line at least posteriorly ; no caudal spot; 
one and sometimes two faint shoulder spots present. Scales and fins 
with dusky points; tip of anal and anterior dorsal ray sometimes black. 
This species is represented by 140 specimens in the present collection, 
ranging in length from 30 to 50 mm. These were taken only in the 
lower part of the Rio Chagres Basin. Although the type is listed from 
the Rio Boqueron, one of the upper tributaries of the Rio Chagres, we 
did not get it there during several days fishing. 
Habitat: Rio Chagres Basin, Panama. 
26. Genus Thoracocharax Fowler. 
Thoracocharax Fowler, Proc. Ac. Nat. Sci. Phila., 1906, 452 (type 
Gasteropelecus stellatus Kner). 
Body strongly compressed, the thoracic region dilated into a semicircu- 
lar disc; abdomen compressed into a sharp keel; dorsal profile anteriorly 
slightly convex; teeth tricuspid or conical, in 2 series on premaxillary; 
