GITON.— EIGENMANNIA. 175 



Fam. 5. GYMNOTID^. 



This family, which has recently been monographed by Eigenmann *, comprises 

 about 30 species from South America, one of which extends into Panama and 

 another as far north as Guatemala. 



The Gymnotidas are highly specialized Characinids, and may be recognized by the 

 long, more or less eel-shaped body, naked or covered with small scales, the restricted 

 gill-openings, the anterior position of the vent, the absent dorsal and ventral fins, the 

 very long anal, and the small or absent caudal. 



Synopsis of the Central- American Genera. 



Each jaw with a series of conical teeth ]. Giton. 



Each jaw with a patch or band of very small villiform teeth 2. Eigenjiannia. 



■ • ■ • 1. GITON, Kaup, 1856. • 



Carajms (non Rafin.), Cuv. Eegne Anim. p. 237 (1817) ; Miill. & Trosch. Hor. Ichthyol. iii. p. 13 



(1845); Giiuth. Cat. Fish. viii. p. 9 (1870). 

 Giton, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 340. 



This genus includes only one species. 



1. Giton fasciatus, Pall., 1769. - 



Carapus fasciatus, Giinth. Cat. Fish. viii. p. 9 (1870) \ 



Giton fasciatus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 340 -. 



Gymnotus carapo, Meek, Publ. Columbian Mus., Zool. vii. 1907, p. 135 '. 



Hah. Guatemala to La Plata ^ ^ ; in Central America known only from the Rio Motai^ua 

 (Salvin) and Lake Amatitlan ^. 



A very variable species, sometimes uniformly coloured, more often witli oblique dark 

 cross-bands which may break up into spots. 

 Total length 400 mm. 



2. EIGENMANNIA, Jord. & Everm., 1896. 

 Eigenmannia, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 341. 

 Four species from Tropical America. 



1. Eigenmannia hnmboldti, Steind., 1878. 



Sternopjgus humboldti, Steiud. Deukschr. Ak. "Wien, xxxix. 1878, p. 71, t. 14. fig. 3 \ and xJi. 



1879, p. 169 -'. 

 Eigenmannia humboldti, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 341 '. 



Hab. Panama, Rio Mamoni^. — Colombia, Rio Magdalena ^. 

 Total length 450 mm. 



* Proc. 'Washington Ac. vii. 1905. 



