Dec. 28, 1916. Fishes of Panama — Meek and Hildebrand. 325 



pressed or pointed, curved inward, this series is followed by a narrow 

 band of minute teeth; scales large, cycloid, 8 or 9 rows between base of 

 dorsal and anal; origin of dorsal in female variable, usually about 

 midway between end of snout and tip of caudal, and posterior to vertical 

 from origin of anal ; its origin in the male is at about the same point as 

 in female, but the fin is higher; caudal fin scaly at base, its margin 

 rounded; anal fin in female usually inserted about midway between tip 

 of snout and base of caudal; anal fin in adult male inserted nearer end 

 of snout than base of caudal, the modified portion very long, slender, 

 more or less needle-shaped, 2.35 to 2.7 in length; ventral fins similar in 

 both sexes, usually failing to reach vent in large females, reaching oppo- 

 site base of anal in males; pectoral fins moderate, i to 1.25 in head. 



Color of sexes similar, olivaceous. Large specimens without cross- 

 bars; young of 60 mm. and less in length with narrow, dark cross-bars 

 on posterior portion of sides. Fins unmarked. 



Of this species we have 80 specimens. The largest female is 150 

 and the largest male 60 mm. in length. It was taken by us only in 

 brackish water about the city of Panama where it is fairly common. 



Fig. 9. Distal part of INTROMITTENT organ of PosciUopsis elongalus (Gunther). 

 (Greatly magnified.) 



We have examined 2 female specimens, paratypes, of P. colombianus 

 (Eigenmann & Henn) . We do not find that they differ essentially from 

 the present species. However, in the absence of male specimens of the 

 former their identity with P. elongatus remains doubtful. 



Habitat: Pacific coast of Panama and probably of Colombia. 



62. Poeciliopsis isthmensis Regan. 



Pceciliopsis isthmensis Regan, Proc. Zool. Soc. London, 1913, 997 



(Colon, Panama), 



Head 3.5 to 3.7; depth 2.5 to 3; D. 9 or 10; A. 10; scales 26 to 28. 



Body robust; mouth small; teeth in narrow bands; interorbital width 

 1.8 to 2 in head; eye 3 to 3.2; origin of dorsal fin midway between 

 anterior margin of the eye and base of caudal, its longest ray 1.5 in 

 head; origin of anal below fourth or fifth ray of dorsal, its first branched 

 ray 1.3 in head; pectoral a little shorter than the head; least depth of 

 caudal peduncle 1.3 to 1.5 in head; in the male the origin of the dorsal is 



