Family XI. Pceciliid^;. 113 



Zoogoncticus robustus Meek, Field Col. Mus. Pub. 65, 1902, 92; 



Ocotlan; Patzcuaro; Zirahuen. 

 Basin of the Rio Lerma. 



FlG. 31. ZOOGONETICUS ROBUSTUS (Bean). 

 No. 43760, U. S. National Museum. 



Head 3 to 3^; depth 3 to 3J3; D. 13 or 14; A. 14 to 16; scales 

 15-38. Body robust anteriorly, compressed posteriorly; head broad, 

 interorbital area nearly flat, its width 2% in head; mouth rather 

 large; lower jaw the longer; chin prominent; snout 3^2 in head; eye 

 4 to 4>2 in head; origin of dorsal fin slightly in front of anal and mid- 

 way between tip of caudal fin and tip of snout ; pectoral fin 1 ^ in 

 head ; ventral fin 2 y^ in head ; caudal fin truncate ; least depth of caudal 

 peduncle 2 in head. 



Color light brownish, much speckled and variegated with darker; 

 on young specimens a tendency to form a narrow dark lateral band 

 on posterior half of body; fins all plain. Length about 5^ inches. 



This species is the largest member of the genus on the Mexican 

 Plateau. Females 4^ to 4^ inches in length, contain from 20 to 38 

 young, each from .67 to .75 inches in length. The young are born 

 in May. 



102. Zoogoneticus maculatus Regan. 



Zoogoncticus maculatus Regan, Ann. & Mag. Nat. Hist., 1904, 

 256; Rio Santiago, Mexico. 



Head 3 (in total length); depth 3^ to 3^; D. 13 or 14; A. 15; 

 scales 36 to 38; mouth moderate, the lower jaw prominent; length 

 of snout equaling diameter of eye, 4 to 4^2 in head; interorbital 2}4 

 to 2){; origin of dorsal fin about midway between posterior edge of 

 preopercle and base of caudal, its longest ray a little longer than 

 the base of the fin, 2 in head (or less) ; origin of the anal a little behind 

 that of dorsal, the first 6 rays in male, short, stiff, and of equal 



