ANNOTATED LIST OF THE SPECIES 325 
Rio Negro to Rio Jurudé and Peruvian Amazon 
15721, 1, 202 mm., Iquitos, Allen, September, 1920. 
454. STERNARCHOGITON PORCINUM Eigenmann and Allen, sp. nov. 
Plate Xeval fig 1 
15740, 1, 300 mm., type, Rio Huallaga, Yurimaguas, Allen, November, 1920. 
15722, 1, paratype, 186 mm., Iquitcs, Allen, September, 1920. 
Not unlike its congener, S. natterer’, differing, however, in several dimensions, 
in the extent of the anal fin; colors also differing considerably. 
Head about 9 in the length; depth 8.5; anal rays about 200; origin of the anal 
fin beneath the middle of the opercle. 
Snout 3.5 in the length of the head; interorbital width 5 in the head length; 
eye about 7 in the snout, and smaller than usual among a small-eyed family; scales 
large, about 4—5 series above the lateral line, pores between the scales toward the 
back, the scales much higher than long; pectoral fin not as long as the head. 
Sides straw-colored, the back dark; posterior half of the pectoral fins and the 
distal half of the anal rays very dark, their basal halves without dark pigmentation. 
The name in allusion to the strong inclusion of the lower jaw within the upper. 
Genus 182: OKEDEMOGNATHUS Myers 
Oedemognathus Myers, 1936, Proc. Biol. Soc. Wash., XLEX, 115. 
Type: Oedemognathus exodon Myers 
Iquitos and lower Peruvian Amazon 
A single specimen, 92 mm. in length, collected by Morris at Iquitos, was de- 
scribed as a new genus and species by Eigenmann and Allen (the present paper). 
In 1936 a similar fish, 202 mm. long, was found and described by Dr. G. 8S. Myers 
from collections made by Mr. William G. Scherer in 1935 for the U. S. National 
Museum, under the present name. 
Caudal fin and dorsal filament present; snout very short; teeth in both jaws 
strong, all those of the upper jaw fixed on the everted lip; those of the lower jaw in 
part antrorse, in part located in the mouth and retrorse; area in front of the dorsal 
filament naked. Similar to Porotergus and Sternarchogiton, but with everted teeth. 
Maxillary oblique, gape short, not quite reaching the vertical from the eye. 
Our specimen differs from the type apparently only in the following par- 
ticulars : 
The eye, while minute, is not covered; that the mandibular teeth are contained 
within the mouth. 
455. OEDEMOGNATHUS EXODON Myers 
Plate XV, figs. 2 and 3 
Oedemognathus exodon Myers, 1936, Proc. Biol. Soe. Wash., XLIX, 115, one, Pebas, Scherer col- 
lection, 
15421, 1, 92 mm., to base of caudal, Iquitos, Morris, 1922. 
