160 OSTARIOPHYSI. 
12. Notropis formosus. 
Moniana formosa, Girard, U.S. & Mex. Bound. Surv., Fish. p. 58, t. 30. figs. 5-9 (1859) °. 
Notropis formosus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 271°; Meek, Publ. 
Columbian Mus., Zool. v. 1904, p. 74’. 
Depth of body 3 to 4 in the length, length of head 32 to 4. Diameter of eye 3 to 33 in the length of head. 
Mouth terminal, oblique ; jaws equal anteriorly ; snout rather pointed. Dorsal 9, with 7 branched'rays, 
its origin equidistant from tip of snout and base of caudal or a little nearer the latter. Anal 8-9. 
Ventrals inserted in advance of the origin of dorsal. 40 to 50 scales in a longitudinal series, 8 to 10 in 
a transverse series from origin of dorsal to lateral line, 4 to 6 between lateral line and base of ventral. 
Lateral line usually complete. Caudal peduncle about twice as long as deep. A lateral stripe on the 
posterior part of the body. 
Hab. Mexico, Rio Casas Grandes in Chihuahua: 
Rio Mimbres!; Colonia Juarez ® (Meek). 
Here described from several specimens, measuring up to 55 mm. in total length. 
13. Notropis aztecus. 
Codoma vittata (non Leuciscus vittatus, De Kay), Girard, U.S. & Mex. Bound. Surv., Fish. p. 53, 
t. 29. figs. 18-21 (1859) *. 
Notropis aztecus, Woolm. Bull. U.S. Fish. Comm. xiv. 1894, p. 63, t. 2°; Jord. & Everm. Bull. 
U.S. Nat. Mus. xlvii. 1896, p. 258°. 
Azxtecula lerme, Everm. & Goldsborough, Bull. U.S. Fish. Comm. xxi. 1902, p. 147, fig. 3*; Meek, 
Publ. Columbian Mus., Zool. v. 1904, p. 60, fig. 14°. 
Aztecula vittata, Meek, t. c. p. 59, fig. 13°. 
Depth of body 33 to 4 in the length, length of head 4 to 43. Diameter of eye 4 to 5 in the length of head. 
Mouth terminal, oblique; jaws equal anteriorly ; snout obtuse, decurved. Dorsal 9, with 7 branched 
rays; origin a little nearer to base of caudal than to tip of snout; longest ray 3 or a little more than 3 
the length of head; free edge straight or convex. Anal 8. Pectoral shorter than the head, not 
reaching the ventrals, which are inserted a little in advance of the origin of dorsal, 43 to 50 scales in 
a longitudinal series, 7 or 8 in a transverse series from dorsal fin to lateral line, 4 or 5 between lateral 
line and base of ventral fin. Lateral line complete. Caudal peduncle nearly twice as long as deep. 
Young with a dark lateral band ending in a caudal spot. 
Hab. Mexico, Rio Lerma System, Valley of Mexico, and upper tributaries of the 
Rio Balsas : 
Lerma‘*® (Meek), Texcoco® (Meek), Chalco®, and Xochimileo (Gadow) in 
Mexico! 22; Puebla in Puebla ®. 
Here described from six specimens, measuring from 45 to 80 mm. in total length. 
13. EVARRA, Woolman, 1894. 
Evarra, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 304. 
Allied to Votropis and evidently derived from a type similar to WV. aztecus, but distinguished by the smaller 
scales, the more elongate and less compressed body, and the broader isthmus, the gill-openings not 
extending forward below to the level of the posterior edge of the preeoperculum, 
Two species from the Valley of Mexico. 
