GOODEA.—GAMBUSIA. 93 
in the length of head ; interorbital width equal to or a little longer than the postorbital part of head. 
32 to 35 scales in a longitudinal series. Dorsal 16-18; origin equidistant from snout and base of caudal 
(do) or nearer the latter(?). Anal 14-16; origin posterior to that of the dorsal. Pectoral 3-4 the 
length of head. Caudal truncate or subtruncate. Olivaceous; a dark spot on each scale of the upper 
and posterior parts of the body; a dark vertical bar at the base of the caudal fin; dorsal and caudal fins 
with dark spots. 
Hab. Mexico, Rio Lerma System : 
Jalisco!; Lake Chapala ?. 
Here described from four specimens, measuring up to 50 mm. in total length, from 
Ocotlan (Meek). 
9. BELONESOX, Kner, 1860. 
Belonesox, Giinth. Cat. Fish. vi. p. 333 (1866); Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, 
p- 684. 
Viviparous. Anal fin, in the male, advanced and modified into an intromittent organ. Mouth large, with 
extended lateral cleft; teeth in bands, slender, pointed, depressible. 
This genus comprises a single species, quite unlike any other member of the family. 
1. Belonesox belizanus. 
Belonesox belizanus, Kner, Sitzungsb. Ak. Wien, xl. 1860, p. 419, fig." ; Giinth. Cat. Fish. vi. p. 333 
(1866) *; Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 684°; Meek, Publ. Columbian 
Mus., Zool. v. 1904, p. 1354. 
Depth of body 4 to 6 in the length, length of head nearly 3. Snout 24 to 32 as long as eye, the diameter of 
which is 5 to 6 in the length of head. Lower jaw more than 3 the length of head. 55 to 65 scales in 
a longitudinal series. Dorsal 9-10. Anal 10-12, in advance of the dorsal. Caudal rounded. <A small 
dark spot on each scale of the upper part of the body; a blackish spot at the base of the caudal. 
Hab. Mexico, Boca del Rio 4, Otopa*, El Hule +, Obispo 4, and Perez * in Vera Cruz ; 
British Honpuras, Belize!; GuateMaLa, Lake Peten ?. 
Here described from eight specimens, measuring up to 200 mm. in total length, from 
Perez (Meek), Lake Peten (Salvin), and Belize. ‘he largest males measure 90 mm. 
10. GAMBUSIA, Poey, 1855. 
Pseudoxiphophorus and Gambusia, Giinth, Cat. Fish. vi. pp. 332 and 333 (1866) ; Jord. & Everm. 
Bull. U.S. Nat. Mus. xlvii. 1896, p. 678. 
Viviparous. Anal fin, in the male, advanced and modified into an intromittent organ. Mouth small or 
moderate ; rami of lower jaw firmly united; small teeth in bands, with an outer series of more or less 
enlarged, conical, fixed teeth. 
This genus comprises ten species from the Southern United States, Mexico, and 
Central America, and three or four from Cuba and Jamaica. 
