160 OSTAEIOPHYSI. 



12. Notropis formosus. 



Moniana formosa, Girard, U.S. & Mcx. 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. 1901, p. 74,'. 



Depth of body 3 to 4 in the length, length of head 3-j to 4. Diameter of eye 3 to 3| in the length of liead. 

 Mouth terminal, oblique ; jaws equal anteriorly ; snout rather pointed. Dorsal 9, witli 7 branehed 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 tho body. 



Ilah. Mexico, Eio 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 (uon Leuciscus viitatus, De Kay), Grirard, U.S. & Mex-. Bound. Surv., Fish. p. 53, 



t. 29. figs. 18-21 (1859) \ 

 Notropis aztecus, Woolm. Bull. U.S. Fisli. Comm. xiv. 1894, p. 63, t. 2' ; Jord. & Everm. Bull. 



U.S. Nat. Mus. xlvii. 1896, p. 258 ^ 

 Aztecula lermee, Everm. & Goldsborougli, 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 31 to 4 in the length, length of head 4 to 4|. Diameter of eye 4 to 5 in the length of head. 

 Jlouth terminal, oblique: jaws equal anteriorly; snout obtuse, deourved. Dorsal 9, with 7 branched 

 rays : origin a little nearer to base of caudal than to tip of snout ; longest ray ^ or a little more than 4 

 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 iu 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 jjeduncle nearly twice as long as deeii. 

 Young with a dark lateral band ending iu a caudal spot. 



JIah. Mexico, Rio Lerma System, Valley of Mexico, and upper tributaries of the 

 Rio Balsas : 



Lerma -^"^ (Meek), Texcoco '^ {Meek), Chalco*^, and Xochimilco {Gadoto) in 

 Mexico 1 2 .3 . Puebla in Puebla*^. 



Here described from six specimens, measuring from 45 to 80 mm. iu total leno-th. 



13. EVARRA, Woolman, 1894. 



Evarra, .lord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 304. 



Allied to Notropis and evidently derived from a type similar to N. (tziecua, but distinguished by the smaller 

 scales, the more elongate and less com])ressed body, and the broader istlimus, the gill-openin"-s not 

 extending forward below to the level of the posterior edge of the proeoperculum. 



Two species from the Valley of Mexico. 



