GAMBUSTA. 



95 



middle of eye to free edge of operculum. 29 to 31 scales in a longitudinal series. Dorsal 8-9 ; origin 

 usually nearer to posterior end of caudal fin than to tip of snout ; free edge of the fin convex. Anal 9-10, 

 similar to the dorsal, ending below or a little in advance of the middle of the dorsal. Pectoral |-f the 

 length of head. Caudal rounded or subtruncate. Least depth of caudal peduncle about | the length of 

 head. Olivaceous ; edges of scales darker ; often a dark longitudinal band from upper part of eye to base 

 of caudal. 



Hah. Streams of the Atlantic Slope from Illinois to Vera Cruz : 



In Mexico recorded from Rio Chihuahua and llio Conchos in Chihuahua ^ ; 

 Monclova in Coahuila^; Monterey and Rio San Diego in Nuevo Leon 3; 

 Matamoros, Rio Soto la Marina, and Rio Panuco in Tamaulipas ^ ; Orizaba ^ and 

 Vera Cruz. 



Here described from specimens measuring up to 70 mm. in total length. 



2. Grambusia bonita. 



39' 



2. Gambusia bonita. 



Gambusia bonita. Meek, Publ. Columbian Mus., Zool. v. 1904, p. 132, fig. 



Depth of body Sj to 3| in the length, length of head 3| to 3-|. Snout shorter than eye, the diameter of 

 which is 2j to 2| in the length of head. Interorbital width equal to the distance from posterior margin 

 of pupil to free edge of operculum. 29 to 31 scales in a longitudinal series. Dorsal 8-10 ; origin a 

 little nearer to posterior end of caudal fin than to tip of snout; middle rays longest. Anal 10-11, 

 simUar to the dorsal, ending below the anterior rays of dorsal. Pectoral 4 the length of head. Caudal 

 rounded or subtruncate. Least depth of caudal peduncle | the length of head. Olivaceous ; scales of 

 upper part of body with dark edges. 



Hah. Mexico, Rio Papaloapam : 

 Refugio ^ Motzorongo i. 



Here described from five specimens, measuring up to 50 mm. in total length, from 

 Refugio, received from Dr. Meek. 



3. Gambusia fasciata. 



Gambusia fasciata, Meek, Publ. Columbian Mus., Zool. v. 1904, p. 129, fig. 37 \ 



Depth of body 3^ to 3|- in the length, length of head 4 to 45. Snout a little shorter than eye, the diameter 

 of which is 3 to 3,'- in the length of head. Interorbital width equal to the distance from middle of eye 

 to free edge of operculum. 32 scales in a longitudinal series. Dorsal 8 ; origin considerably nearer to 

 end of caudal than to tip of snout ; middle rays longest. Anal 9-10, similar to the dorsal, ending below 

 the orio-in of dorsal. Pectoral 4 the length of head. Caudal subtruncate. Least depth of caudal peduncle 

 3 the lenoth of head. 4 or 5 narrow vertical or slightly oblique blackish bars on each side; a small 

 blackish spot on the anterior dorsal rays, another on the anal. 



Hah. Mexico, Oaxaca, Tequesixtlan [Gadow), San Geronimo 1, Tehuantepec 1. 

 Here described from six specimens, measuring up to 55 ram. in total length. 



4. Gambusia tridentiger. 



Gambusia tridentiger, Garm. Mem. Mus. Comp. Zool. xix. 1895, p. 89 '. 



Inner teeth tricuspid. 28 to 30 scales in a longitudinal series. Dorsal 7-8 ; origin about equidistant from 

 occiput and end of caudal, nearly above the last ray of anal. Anal 10. 7 or 8 brownish vertical bars, 

 separated by pale interspaces of equal width, on the posterior part of the body. 



Hah. Isthmus of Panama ^, 



