130 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



Head 4^4', depth 3! to 4; D. 7 ; A. 7 ; scales 8-32. Body elongate, 

 not much compressed; head small, flat above; interorbital 2 in head; 

 mouth small; jaws about equal; teeth in jaws in a band, the outer 

 series enlarged; all of the teeth conical; snout 3^ in head; eye 3 in 

 head ; origin of dorsal to base of caudal i K m its distance from tip of 

 snout, about midway between base of caudal and middle of pectoral fin ; 

 anal fin (?) in advance of dorsal; pectoral fin i% in head; ventral 2% ; 

 caudal fin truncate; least depth of caudal peduncle \% in head; ali- 

 mentary canal i| times total length of the fish; peritoneum black. 



Color light brownish ; a dark vertebral streak ; side with from 3 to 5 

 narrow vertical bars which extend from dorsal region to middle of side, 

 occasionally one or two bars reaching ventral region ; a black spot on 

 first two dorsal rays near their base ; region in front of anal and basal 

 half of first rays black; iris black; a dark line on under side of 

 caudal peduncle. Length 2 inches. 



One female contained 27 eggs, young quite well developed. 



119. Gambusia gracilis (Heckel). 



Xiphophorus gracilis Heckel, Sitzgsber. Akad. Wiss. Wien, 1848, 

 300; Orizaba, Mexico. 



Gambusia gracilis Garman, Memoirs, Mus. Comp. Zool., xix, 1895, 

 85; Mexico and Central America: Jordan & Evermann, Bull. 

 47, U. S. Nat. Mus., 1896, 683: Meek, Field Col. Mus. Pub. 65, 

 1902, 99; Puente de Ixtla; Balsas. 



Streams on both sides of the divide south of the City of Mexico. 

 (Cuautla; Yautepec; Jojutla; Chietla.) 



Head 4; depth 3^3 to 3; D. 6; A. 9; scales 8-30. Body rather 

 slender, not much compressed; head small, mouth small, lower jaw 

 the longer, teeth in the outer series enlarged; snout pointed, 3^ in 

 head; diameter of eye 3 > ; origin of dorsal fin (?) behind that of anal, 

 its distance from base of caudal i ^ in distance from tip of snout ; pec- 

 toral fin i % in head ; ventral 2 ; caudal fin rounded ; least depth of 

 caudal peduncle if in head; peritoneum dark; alimentary canal 

 shorter than the length of the fish. 



Color dark brownish, each scale with light edgings; no spots on the 

 fins ; a broad dark lateral band more or less broken up into short ver- 

 tical bars; iris black. Length about 2 inches. 



The young are probably born early in May. 



120. Gambusia affinis (Baird & Girard). 



Heterandria affinis Baird & Girard, Proc. Acad. Nat. Sci. Phila., 

 1853, 390; Rio Medina and Rio Salada, Texas. 



Heterandria nobilis Baird & Girard, Proc. Acad. Nat. Sci. Phila., 

 1853, 390; Comanche Spring, Rio Grande. 



