1004 MR. C. TATE REGAN ON 



Depth of body about 2| in the length, length of head about 4. 

 23 to 27 scales in a longitudinal series. Dorsal 9-11 ; origin 

 equidistant from snout and anterior part of caudal. Anal 7-8, 

 opposite posterior ^ of doi-sal. Blackish or brownish above, 

 yellowish below, the two colours sharply separated. 



Rio San Juan at Monterey. 



2. Platypcecilus MACULATUS. (Text-fig. 1 72 D.) 



riatypoecilus maculatus Giinth. Cat. Fish. vi. p. 350 (1866). 



Poecilia macidata Regan, Biol. Centr.-Amer., Pisces, p. 105 

 (1907). 



Closely related to P. couchianus. Depth of body 2 to 2| in 

 the length, length of head 3^ to 3|. Anal 8-9. Olivaceous ; a 

 dark spot or crescent or a pair of spots at base of caudal. 



Atlantic Coast streams of Mexico and Guatemala. 



22. XiPHOPHORUS Heckel, 1848. 



Sitzungsb. Akad. Wien, i. p. 291. 



Closely related to the preceding, as is shown by the great 

 similarity in the structure of the anal hns of the males (text-fig. 

 172 E). The species occur in rivers of the Atlantic Slope from 

 Tamaulipas to Guatemala. After examination of a large series 

 of specimens I conclude that only 3 species are well established. 



1. XiPHOPHORUS MONTEZUMA. 



Jord. & Snyder, Bull. U.S. Fish. Oomm. 1900, p. 131, fig. 11 ; 

 Regan, Biol. Centr.-Amer., Pisces, p. 107 (1907). 



Dorsal 11-13. Anal 6-8. Scales 27 to 29. Depth about 3 

 in the length, length of head about 4. Yellowish ; scales of 

 upper pai-t of body dark-edged ; usually a dark lateral stripe. 



Rio Panuco, Mexico. 



2. XiPHOPHORUS HELLERi. (Text-fig. 172 E.) 



Heck. Sitzungsb. Akad. Wien, i. 1848, p. 291, pi. viii. ; Giinth. 

 Cat. Fish. vi. p. 349 (1866); Regan, Biol. Centr.-Amer., Pisces, 

 p. 107 (1907). 



Xiphophorus guentheri Jord. & Everm. Bull. U.S. Nat. Mus. 

 xlvii. 1896, p. 702. 



Xiphophorus jalapoe Meek, Publ. Columbian Mus., Zool. v. 

 1903, p. 136, pi. xi. 



Xiphopihorus strigatus Regan, t. c. pi. xiv. fig. 7. 



Dorsal 11-14. Anal 8-10. Scales 26 to 30. Depth 3 to 4 

 in the length, length of head 4 to 44. Sides of body blue, with 

 red stripes between the series of scales. 



Southern Mexico ; Guatemala. 



Mexican examples have nearly always a strong stripe from eye 

 to base of cavidal {strigatus), the males sometimes with another 

 backwards from axil of pectoral {helleri, jalapce) ; in specimens 



