DEC. 28, 1916. FISHES OF PANAMA MEEK AND HILDEBRAND. 323 



reaching about one-third the distance to eye; teeth pointed, in bands in 

 the jaws, the outer ones slightly enlarged; scales moderate, cycloid, ex- 

 tending to tip of snout and on base of caudal; caudal peduncle strongly 

 compressed, its least depth 1.5 to 1.8 in head; origin of dorsal in female 

 over base of last ray of anal, and about midway between posterior 

 margin of eye and base of caudal; in the male the origin of the dorsal is 

 about midway between tip of snout and base of caudal; caudal rather 

 pointed; anal fin in female inserted considerably nearer end of snout 

 than tip of caudal, its posterior margin convex; origin of anal in adult 

 male is about half as far from end of snout as from tip of caudal, the 

 produced portion failing to reach base of caudal by about the length 

 of post-orbital part of head, its length 2 to 2.25 in body, the anterior 

 branch of the second produced ray the longest, directed forward at 

 apex, the first produced ray a little longer than the third, no spur; 

 ventral fins reaching to or slightly past vent in female, and notably 

 past origin of anal in male; pectoral fins reaching at least to middle 

 of ventrals, i to 1.4 in head. 



Color of the sexes similar, grayish green; posterior part of body 

 with 4 or 5 indistinct, dark cross-bars; a dark line from anal to base of 



FIG. 8. DISTAL PART OF INTROMITTENT ORGAN OF Prioptchthys panamensis sp. nov. 



(Greatly magnified.) 



caudal; dorsal fin with dark chromatophores at base of the posterior rays 

 and again at the tips of these rays; usually with a more or less distinct 

 dark area about vent. 



Of this species we have 37 specimens. The largest female is 37 

 and the largest male 24 mm. in length. One specimen is from the Rio 

 Chame and all the others from a brackish pool at Chame Point on the 

 Pacific coast. 



In general appearance this fish resembles Priapichihys tridentiger, 

 but the intromittent organ of the male is quite different, the caudal fin 

 is more pointed and bears more scales on its base, the color is paler, and 

 the cross-bars are fewer. 



Type a male 24 mm. in length, from Chame Point. 



