170 OSTARIOPHYSI. 
Anal 20-27 (3-4/17-24) ; maxillary extending to below anterior part or 
middle of eye; diameter of eye 2? to 34 in the length of head (in specimens 
of 60 to 120 mm.). woe ee es 
II. Interorbital width 3} to 34 in the length of head; 14-17 gill-rakers 
on the lower part of the anterior arch . . . . 
oe ew wl ee) 68. mexicanus. 
. . . 4 angustifrons. 
1. Tetragonopterus seneus. 
Tetragonopterus eneus, Gtinth. Proc. Zool. Soc. 1860, p. 319’, and Cat. Fish. v. p. 326 (1864) *; 
Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 334°. 
Tetragonopterus fasciatus (part.), Giinth. Cat. Fish. v. p. 822 (1864) *. 
Tetragonopterus microphthalmus (part.), Ginth. t. c. p. 324°. 
Tetragonopterus panamensis, Giinth. 1. ¢.°; Steind. Denkschr. Ak. Wien, xli. 1879, p. 166, t. 1. 
figs. 1 & 2". 
Tetragonopterus humilis, Giiuth. t. c. p. 827°. 
Tetragonopterus finitimus, Bocourt, Ann. Sci. Nat. (5) ix. 1868, p. 62°; Vaill. & Pellegr. Bull. 
; Mus. Paris, 1903, p. 825°. 
Tetragonopterus belizianus, Bocourt, 1. c."; Vaill. & Pellegr. 1. c.”. 
Tetragonopterus cerstedii (Kroyer, MS.), Liitken, Vid. Medd. 1874, p. 229 an 
Tetragonopterus rutilus (part.), Jord. & Everm. |}. ¢.”*. 
Tetragonopterus eneus (part.), Meek, Publ. Columbian Mus., Zool. v. 1904, p. 86 an 
? Astyanax nasutus, Meek, Publ. Columbian Mus., Zool. vii. 1907, p. 108 *, 
Astyanax rutilus erstedii, Kigenmann & Ogle, Proc. U.S. Nat. Mus. xxxiii. 1907, p. 22. 
Astyanaz rutilus nicaraguensis, Eigenmann & Ogle, t. c. p. 23”. 
Astyanaz rutilus eneus, Kigenmann & Ogle, t. c. p. 24”. 
Astyanax fischeri, Kigenmann & Ogle, t. c. p. 26”. 
Depth of body 24 to 34 in the length, length of head 33 to 43. Snout obtuse, not longer than eye, the 
diameter of which is 3 to 34 in the length of head; interorbital width 24 to 3 in the length of head. 
Maxillary extending to the vertical from anterior edge of eye or sometimes a little beyond; maxillary 
teeth 0 to 6. 11 to 15 gill-rakers on the lower part of the anterior arch. 32 to 40 scales in a 
longitudinal series, 6 to 8 in a transverse series from dorsal fin to lateral line, 5 to 7 between lateral line 
and root of ventral fin. Dorsal 10-12; origin behind the ventrals ; longest ray from 3 to as long as the 
head ; free edge of the fin nearly straight. Anal 25-33, with 3 or 4 simple and 22 to 29 branched rays; 
free edge usually slightly emarginate. Pectoral from 7 to as long as the head, usually reaching the 
ventrals, which often extend to the origin of anal. Caudal forked. Caudal peduncle about as long as 
deep. Olivaceous above, silvery below ; a bluish-silvery lateral band ; often a dark humeral spot; usually 
a blackish oblong spot on the caudal peduncle, produced on the middle caudal rays. 
Ilab. Mexico!®, Rio Papaloapam (Buller, Gadow, Meek), Oaxaca’ (Sallé); Brivisn 
Honpuras 1112 (Paris Mus., Robertson); GuatemMatal®, Rio Motagua‘, Lake 
Yzabal ®, Huamuchal 4, Rio Guacalate*, and Lake Amatitlan °° (Godman & Salvin), 
Chinautla 91°; Nicaragua !7, Lake Nicaragua!’, Lake Managua 1!® and Rio San 
Juan 13 (Copenhagen Mus.) ; Costa Rica (Underwood); Panama’? (Godman & 
Salvin), Rio Mamoni’, Rio Chagres. 
Here described from a large series of specimens, measuring up to 120 mm. in total 
length, including the types of the species and of 7. microphthalmus, T. panamensis, 
and T. humilis, and co-types of 7. erstedii and T. belizianus. 
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