Dec. 28, 1916. FisHes or PANAMA— MEEK AND HILDEBRAND. 309 
in lower jaw; frontal and parietal fontanels present; caudal peduncle 
round or compressed, without caudal fin; scales small, cycloid; lateral 
line complete; origin of anal in pectoral region; posterior air bladder 
conic. Size moderate or rather large. 
59. Sternopygus dariensis sp. nov. 
Type No. 8949, F. M. N. H.; length 300 mm.; Marrigante, Rio 
Tuyra, Panama. 
Head 5.95 to 7.7 in length to end of anal; depth 6.65 to 7.8; A. 256 
to 292. 
Body elongate, more or less eel-shaped, compressed; head small, 
its upper profile usually slightly concave; snout rather slender, not 
much deeper than wide, its length 2.2 to 3 in head; eye small, with a free 
orbital margin, 3.1 to 7.25 in snout; interorbital 4.85 to 6.66 in head; 
_ mouth moderate, the gape reaching about half way to eye; upper jaw 
a little in advance of the lower, the latter included at sides; teeth in 
the jaws villiform, those of the upper jaw separated into two patches 
by a median line; gill-slit scarcely as long as snout; vent 3 or 4 times 
diameter of eye behind vertical from posterior margin of orbit; 
caudal peduncle varying in length, from notably shorter than head 
to a little longer than head, rather robust, compressed; lateral line 
complete, following the outline of the back; scales very small, cycloid; 
origin of anal below or a little behind base of pectorals, the longest 
rays a little shorter than snout; pectoral fins small, 2.1 to 2.75 in 
head. 
Color grayish brown, the back slightly darker than the rest of body; 
sides with numerous dusky punctulations. Fins unmarked. 
This species is represented by 25 specimens, ranging from 124 to 
810 mm. in length. All were taken below the head of tide water at 
Marrigante on the Rio Tuyra. We have designated as the type a 
specimen 300 mm. in length. 
This species differs from S. macrurus, its nearest relative, in the 
slightly concave profile of head, more slender snout, smaller eye, nar- 
rower interorbital, in the shorter and much heavier tail, and in the 
slightly more posterior position of the vent. 
35. Genus Hypopomus Gill. 
Hypopomus Gill, Proc. Ac. Nat. Sci. Phila., 1864, 152 (type Rham- 
phichthys miillert Kaup). 
Brachyrhamphichthys Gianther, Cat. Fish. Brit. Mus., VIII, 1870, 6 
(type Rhamphichthys artedi Kaup). 
