82 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



Hybopsis altus Woolman, Bull. U. S. Fish Comm., 1894, 61; 

 Rio Lerma, Salamanca, Queretaro : Jordan & Evermann, Bull. 

 47, U. S. Nat. Mus., 1896, 322: Jordan & Snyder, Bull. U. S. 

 Fish Comm., 1900, 125; Rio Verde; Aguas Calientes: Pellegrin, 

 Bull. Mus. Nat. Hist. Paris, 1901, 205 ; Estado de Jalisco: Meek, 

 Field Col. Mus. Pub. 65, 1902, 86; Acambaro; Celaya; Aguas 

 Calientes; Lagos. 

 Notropis altus B. A. Bean, Proc. U. S. Nat. Mus., 1898, 539; Rio 



Cuitzeo, Michoacan. 

 Basin of the Rio Lerma. 



Head 3^3 to 4; depth 3^ to 4; scales 9-46-4. Body rather 

 elongate, compressed, back elevated; head low, rather long; snout 

 bluntish; mouth terminal, large; end of maxillary reaching slightly 

 beyond vertical from anterior margin of orbit, its length 3 > in head; 

 snout 3^i in head; jaws equal; teeth 4-4, with grinding surface and 

 tips slightly hooked; maxillary barbel rather small; eye 4^ in head; 

 origin of dorsal fin slightly nearer tip of snout than base of caudal; 

 pectoral fins pointed, i% in head; ventrals if- in head: caudal fin 

 forked; caudal peduncle strong, its least depth 2% in head; lateral 

 line complete, slightly decurved. 



Color light olivaceous, lighter below; sides above lateral line with 

 a more or less plumbeous lateral band; no caudal spot. Length about 

 10 inches. 



This species is usually found in clear running water. It is quite 

 abundant in the upper tributaries of the Rio Lerma, from which 

 streams only, it is known. Sexual organs of specimens taken the third 

 week of May not developed. Evidently it spawns late in the summer. 



33. Couesius Jordan. 



Couesius Jordan, Bull. Hayden's Geol. Sur. Terr., iv, 785, 1878. 

 (Type, Nocomis milneri Jordan.) 



Body elongate; head normal, not depressed; the profile convex; 

 mouth terminal, normal; a well-developed barbel on the anterior 

 side of the maxillary, just above its tip; teeth 2, 4-4, 2, hooked, with- 

 out grinding surface; scales rather small; lateral line complete. 



78. Couesius adustus Woolman. 



Couesius adustus Woolman, Bull. U. S. Fish Comm., 1894, 57; Rio 

 Conchos, Chihuahua: Jordan & Evermann, Bull. 47, U. S. 

 Nat. Mus., 1896, 325. 

 Rio Conchos in Chihuahua. 



Head 4% ', depth 4^3 ; D. 8 ; A. 7 ; scales 13-58-8. Body moderate- 

 ly compressed, the back little elevated, the anterior profile rather 



