Family XI. Pceciliid^;. 149 



.:& 





Fig. 47. Heterandria LUTZI Meek. 

 No. 3718, Field Columbian Museum. 



appearance; snout 3^2 in head; eye large, 3% in head; teeth movable, 

 in one series, conical, curved backward at the tips; origin of dorsal 

 slightly behind that of anal in females, midway between base of caudal 

 fin and posterior margin of opercle ; base of dorsal 3 in head ; its height 

 1 x /i ; pectoral 1 ]A, ; ventral 2 ; caudal fin truncate ; caudal peduncle 

 slender, its least depth 1^ in head; alimentary canal much convoluted, 

 not in definite coils, its length about x% times the total length of the 

 fish; peritoneum black. 



Color olivaceous, a narrow dark lateral band broken into small 

 round or oblong spots, each scarcely as large as pupil; iris black; a nar- 

 row dark streak on under side of caudal peduncle; a faint vertebral 

 streak, more conspicuous in the young. Length about 3 V 2 inches. 



One female 2.59 inches in length contained 40 young, each about 

 .35 inch in length. The males are about half as large as the females. 



61. Poecilia Bloch & Schneider. 



Pcecilia Bloch & Schneider, Syst. Ichthy., 452, 1801. (Type, Pcecilia 

 vivipara Bloch & Schneider.) 



Body oblong, often rather deep; mouth small, transverse, with 

 weak jaws; teeth small, in narrow bands, the outer teeth enlarged, 

 curved, and movable; scales large; dorsal fin small, of 7 to n rays; anal 

 fin short, in female nearly opposite dorsal, in males advanced and 

 modified into a sword-shaped intromittent organ ; alimentary canal long ; 

 vertebrae about 28. Sexes about equal in size. 



KEY TO THE SPECIES OF PCECILIA. 



a. Anal rays 9 or 10; sides with a black lateral page 



stripe as wide as eye; scales 8-29 occidentalis 150 



