MAY, 1902. THE ICHTHYOLOGY OF MEXICO MEEK. 107 



female, 3.75 inches in length. The males average smaller than 

 the females. Puente de Ixtla; Balsas; La Antigua. 



Xiphophorus jalapae, sp. nov. 



Type, No. 3724, F. C. M. Length, 2.76 inches. 



Locality, Jalapa, Vera Cruz, Mexico. 



Head 4; depth 3!; D. 13; A. 9; scales 28-8. Body elongate, 

 not very robust, but with a deep caudal peduncle; head flattish, 

 wedge-shaped; mouth rather small, lower jaw the longer; outer 

 series of teeth pointed and loose, behind which is a band of 

 smaller conical pointed teeth; peritoneum black; intestinal canal 

 elongate, on ventral surface and right side, with 4 coils on the 

 right side, its length i ^ the length of the body. 



Eye large, 3 in head; snout 3^; interorbital broad, little con- 

 vex, its width 2 in head; base of dorsal i! in the head, longest 

 dorsal ray if in head (in $ i| in head); pectoral il in head; 

 ventrals i|; caudal sub.-truncate; origin of dorsal fin midway 

 between base of caudal and middle of snout, being well in 

 advance of the anal. The male is more slender than the female. 

 Head of male 4!, depth 4. Caudal appendage pointed, its 

 length 1 1 in the length of the body. Modified anal of the male 

 rather short and thick, length i in head; a notch on under side 

 near its tip; ventrals of male long, slender, and pointed, their 

 tips nearly reaching tip of anal fin; length of ventral fin of male 

 equal to length of the head; origin of ventrals in both sexes well 

 in advance of dorsal fin. 



Female, olive brown above, nearly plain white below; tfhese 

 colors are separated by a narrow lateral band, which extends 

 around snout on upper half of the body; the middle of each scale 

 is darker, giving faint brownish lines on side; a dark line on 

 under side of caudal peduncle; dorsal fin with two rows of black 

 spots near the base, other fins plain. 



The color of the male is similar to that of the female, except 

 the dark lateral band extends on caudal and forms the upper 

 black margin of caudal appendage. There is a second lateral 

 band from lower angle of pectoral to origin of anal fin, and a 

 dark streak on ventral surface of caudal peduncle which forms 

 the lower black margin of caudal appendage. In life the middle 

 of caudal appendage and lighter portion of lower half of the body 

 is a bright yellow. Dorsal fin on both sexes spotted. Longest 

 female, 2.95 inches. Longest male (without appendage), 3 inches 

 in length. 



