128 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



Bull. 47, U. S. Nat Mus., 1896, 678: B. A. Bean, Proc. U. S. 

 Nat. Mus. 1898, 541; Mirador: Meek, Field Col. Mus. Pub. 65. 

 1902, 98; Jalapa. 



Pseudoxiphophorus pauciradiatus* Regan, Ann. & Mag. Nat. Hist., 

 1894, 256; Orizaba, Vera Cruz. 



Streams of the eastern slope of Mexico from Jalapa to the Isthmus 

 of Tehuantepec. ''Jalapa ; Xico ; Cordoba ; Otopa : Motzorongo ; El Hule ; 

 Obispo; Perez; Sanborn.) 



Head 4; depth 3^ to 4; D. 13 to 15 ; A. 8 or 9; scales 9-30. Body 

 elongate, rather robust, not much compressed; head depressed for- 

 ward; interorbital nearly flat, i in head; snout 2^ to 3; eye 3^; 

 origin of dorsal fin in advance of anal (?), midway between base of 

 caudal and tip of snout, or slightly nearer base of caudal; the base of 

 the dorsal very long, about y* longer than the head ; pectoral fin short 

 and broad, 1^3 in head; ventral fin 2 in hea.d; caudal fin rounded ; 

 caudal peduncle robust, 1% in head. 



Color dark brownish; posterior margin of each scale black, making 

 prominent outlines on scales ; a large black blotch on upper y$ of base 

 of caudal ; some black on membrane of dorsal fin ; a black band across 

 middle of anal. Length about 3% inches. 



This species is very variable, and is quite plentiful in all streams 

 of Vera Cruz from Jalapa to Sanborn. At Xico, the highest point 

 from which I made collections, it was the only species taken. The 

 largest specimens collected are from Cordoba, the longest being about 

 3.50 inches. One female from Cordoba, 3.35 inches in length, con- 

 tained 45 eggs, each .115 inch in diameter. The young are probably 

 born in May. 



52. (rambusia Poey. 



GUAZACONES. 



Gambusia Poey, Memorias, i, 382, 1855. (Type, Gambusia punctata 



Poey.) 



Body elongate, more or less compressed; mouth moderate, the 

 lower jaw projecting; each jaw with a band of pointed teeth, the outer 



*Mr. C. T. Regan admits two species in this genus. He says: "It 

 (Pseudoxiphophorus bimaculatus Heckel) differs from Pseudoxiphophorus pauci- 

 radiatus Regan in having a longer head and longer snout, and in the dorsal fin 

 with 14 to 1 6 rays commencing midway between tip of snout and base of 

 caudal, its base about ^ of the total length. P. pauciradiatus Regan has D. 

 ii to 13, origin of dorsal nearer base of caudal than to tip of snout, the length 

 of its base about 4 times in the total length." 



The species is very variable. In some specimens in the museum collection 

 from Cordoba the base of the dorsal fin is longer than head, in others equal to 

 or shorter, the number of rays in dorsal fin is 13 to 15, very seldom 12 or 16. 

 This species ranges from about 6,000 feet to sea level. 



