154 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



row, small, pointed, and loosely attached; dorsal fin in advance of 

 anal, midway between base of caudal and posterior margin of eye; 

 the dorsal fin in old males extremely high, its longest rays a half 

 longer than head; pectoral i i-io in head; ventral i^', caudal fin 

 rounded, in old males much expanded and fan -like; caudal peduncle 

 very deep, i in head in females to about equaling length of head 

 in old males ; alimentary canal very elongate, coiled on the right side. 



Color light brownish above, belly a shade lighter; the edges of the 

 scales usually light, forming more or less indistinct lateral stripes 

 along the rows of scales. Length about 3 inches. 



In general coloration this species is very variable. In some 

 specimens nearly half the scales on the side have black centers ; males 

 usually have light vertical bars, and the dorsal and caudal fin with 

 many black spots arranged in regular rows, the fins being transversely 

 barred, and the edges are light yellowish, sometimes with a narrow 

 dark border. The caudal and dorsal fins of males may have dark 

 blotches. Some of the males may have dark blotches scattered over 

 the side of the body and caudal and dorsal fins; occasionally these 

 blotches may be so numerous as to form the body-color of the fish. 

 The color of the females is more uniform than that of the males. -A 

 very variable and widely distributed species. It is probable that a few 

 of the Pcecilia described from Central America belong to this species. 



62. Mollieiiesia Le Sueur. 

 Mollienisia Le Sueur, Jour. Acad. Nat. Sci. Phila., 1821, 3, pi. in. 



(Type, Mollienisia latipinna Le Sueur.) 



Body rather stout; mouth small; mandible very short, its bones 

 united, the dentary being movable; outer edge of both jaws with a 

 narrow band of small teeth, the outer series long, slender, and 

 movable, with tips curved and slightly compressed; dorsal fin over 

 or in advance of the anal (in female); the anal fin of the male 

 placed forward and modified into an intromittent organ ; lower angle 

 of caudal in the male slightly produced; alimentary canal elongate, 

 with numerous convolutions; dorsal fin of male very high; vertebrae 

 17 + 13=30. 



Small mud-eating fishes of swamps near the coasts from North 

 Carolina to Mexico. 



KEY TO THE SPECIES OF MOLLIENESIA. 

 a. Head large, 3^ in body; dorsal rays 12 or 13; PAGE 



origin of dorsal fin over that of anal in females formosa 155 



aa. Head 3 % to 4 in body; dorsal rays 13 to 16; 



origin of dorsal fin in advance of anal in female .... latipinna 155 



