324 Fretp Museum or Natura History — Zodtoey, Vor. X. 
40. Genus Peeciliopsis Regan. 
Peciliopsis Regan, Proc. Zool. Soc. London, 1913, 996 (type Pecilia 
presidionis Jordan & Culver). 
Body elongate, compressed; head more or less depressed; mouth 
small, the cleft transverse; teeth in the jaws in 2 series or bands, de- 
pressable, the outer ones largest, slightly compressed; the intromittent 
organ long and slender, without hooks or serrations at apex; ventral 
fins not modified in the male. 
KEY TO THE SPECIES. 
a. The three produced rays of anal, as well as both branches of the 
second, all of about equal length and reaching to apex of intro- 
mittent organ, failing quite notably to reach base of caudal when 
deflexed; no dark area over vent; young of 60 mm. and less in 
length with dark cross-bars on posterior part of body; fins un- 
marked. elongatus, p. 324. 
aa. The first and the anterior branch of the second produced ray of 
anal fin in male of about equal length and extending to apex 
of intromittent organ, the posterior branch of the second 
and the third produced ray notably shorter; intromittent 
organ when deflexed reaching nearly or quite to base of caudal; 
a dark area over vent; indistinct cross-bers on body; fins dusky, 
the dorsal with blackish basal band and dark edge. 
isthmensis, p. 325. 
61. Poeciliopsis elongatus (Giinther). 
Pecilia elongata Ganther, Cat. Fish. Brit. Mus., VI, 1866, 342 (Panama), 
and Trans. Zool. Soc. London, VI, 1869, 484, Pl. LXXXYV, fig. 2 
(Panama); Jordan & Evermann, Bull. U. S. Nat. Mus., XLVII, 
1896, 697; Gilbert & Starks, Mem. Cal. Ac. Sci., 1904, 50 (Brackish 
sloughs about Panama); Regan, Biol. Cent. Amer., Pisces, 1907, 102. 
Mollienisia elongata Regan, Proc. Zool. Soc. London, 1913, 1013 (Panama). 
?Heterandria colombianus Eigenmann & Henn, Indiana Univ. Studies, 
No. 16, 1912, 27 (Rio Dagua, Colombia); Regan, Proc. Zool. Soc. 
London, 1913, 996. 
?Peciliopsis colombianus Henn, Ann. Carnegie Mus., X, 1916, 120 
(Rio Dagua, Colombia). 
Head 3.4 to 4.4; depth 3.4 to 4; D. 8 to ro, usually 9; A. 8 or 9; scales 
28 to 33. 
Body elongate, robust, posteriorly compressed; head depressed, flat 
above; snout broad, 3.8 to 4.55 in head; eye 3.33 to 4.6; interorbital 2 
to 2.2; mouth transverse; teeth in outer series close-set, slightly com- 
