Dec. 28, 1916. Fishes oF PANAMA— MEEK AND HILDEBRAND. 327 
Xiphophorus gillii Kner & Steindachner, Abhandl. K. Bayer. Ak. Wiss. 
Manchen, X, 1864, 28, Pl. IV, fig. 1 (Rio Chagres, Panama). 
Platypacilus mentalis Gill, Proc. Ac. Nat. Sci. Phila., 1876, 335 (Panama); 
Jordan & Evermann, Bull. U.S. Nat. Mus., XLVII, 1896, 686. 
Pecilia boucardi Steindachner, Sitzb. K. Ak. Wiss. Wien, LXXVI, 
1878, 386, Pl. III, figs. 2 & 3 (Colon, Panama); Jordan & Evermann, 
Bull. U.S. Nat. Mus., XLVII, 1896, 695; Gilbert & Starks, Mem. 
Cal. Acad. Sci., 1904, 51 (Streams near Panama). 
Pecilia gillii Garman, Mem. Mus. Comp. Zool., XIX, 1895, 63 
(Panama). 
Mollienisia sphenops Regan, Proc. Zool. Soc. London, 1913, 1012, fig. 
173, F (in part); Henn, Ann. Carnegie Mus., X, 1916, 136 (Carta- 
gena, Colombia). 
» Head 3.15 to 4; depth 2.65 to 3.75; D. 10 or 11; A. 10; scales 27 to 30. 
Body compressed; head depressed, flat above; snout broad, its 
length 3.2 to 4 in head; eye 3.1 to 3.9; interorbital 1.85 to 2.4; mouth 
small, the cleft transverse; teeth in the outer series slender, movable, 
somewhat broadened and hooked at apex; inner teeth in a band, small, 
tricuspid; scales moderate, cycloid, 8 longitudinal rows between base of 
dorsal and anal; origin of dorsal in female a little in advance of anal, and 
somewhat nearer end of snout than tip of caudal, its base about equal to 
length of longest rays; in the male this fin is much higher and the base 
is equal to about two-thirds the length of the longest rays; caudal fin 
scaly at base, its margin rounded; anal fin in female inserted about 
equidistant from end of snout and tip of caudal, the anterior rays not 
produced; in the male this fin is inserted equidistant from end of snout 
and base of caudal, the produced portion 1.2 to 1.45 in head, the first 
and the two branches of the second produced ray of about equal length, 
the anterior ray bearing a small antrorse hook at apex, the third with a 
process directed downward and backward at its apex; in advance of the 
intromittent organ lies a sort of hood which is not attached to the distal 
portion of this organ; ventral fins normal in the female, reaching vent; 
in the male the first articulated ray is produced, reaching notably 
beyond base of anal; pectoral fins rather long, 1.05 to 1.7 in head. 
Color olivaceous, dorsal and caudal fins with dark dots. The color 
of specimens from salt and brackish water is more variable than those 
taken in fresh water. The markings on Atlantic slope specimens are 
more distinct than on those from the Pacific side. The color markings 
of specimens from Colon agree with those from Vera Cruz, Mexico; 
most of the specimens have a black spot on each scale forming lines 
along the rows. These spots are-seldom present on the Pacific side 
specimens and when present are not very distinct. The males often have 
