162 OSTAEIOPHYSI. 



very long, slender, and numerous. 60 to 70 scales in a longitudinal scries. Dorsal 9-10, with 



7 bi-anchcd rays ; origin equidistant from tip of snout and base of caudal and above the insertion of (he 

 vcntrals. Anal 8-10, with 6 or 7 branched rays. Silvery, back darker ; fins plain. 



Ilal). Mexico, Lake Chapala in Jalisco ^ " [Buller, Meek). 



I have examined three specimens, 200 to 230 mm. in total length. 



16. STYPODON, Garm., 1881. 

 Stijpodun, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. ISDG, p. 2.20. 



Body oblong, compressed. Mouth small, protractile ; no barbels. Pharyngeal teeth cylindrical, -with conves 

 apices, in a single series, 3 — 3. Scales large (35 in a longitudinal series) ; lateral line complete, 

 decurved. Dorsal and anal fins short. 



A single species from Coahnila. 



1. Stypodon signifer. 



Stypodon siynifer, Garm. Bull. Mus. Comp. Zool. viii. 1881, p. 90'; Jord. & Evcrm. Bull. U.S. 

 Nat. Mus. xlvii. 1896, p. 220'; Meek, Publ. Columbian Mas., Zool. v. 1904, p. .51 \ 



Hah. Mexico, Lake Parras in Coahnila i. 



17. PIMEPHALES, Eafin., 1820. 



Pimephales, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 189G, p. 210. 



Body more or less elongate, moderately compressed. Mouth small, inferior, protractile; no barbels. 

 Pharyngeal teeth with oblique grinding-surfaco, usually not hooked, in a single series, 4 — 4. Scales 

 moderate. Dorsal and anal fins short, the former with the first ray more or less spinous (in adult males 

 covered by a thick skin) and separated from the second by a membrane. Intestine elongate. 



Three or four species from the United States and Northern Mexico. 



1. Pimephales confertus. 



Hyborhynclms confertus, Girard, Proc. Ac. Philad. 1856, p. 179'. 



Pimephales promelas confertus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 189G, p. 217 ■'. 



PiMelocepliates coaferlus, ]\Icek, Publ. Columbian Mus., Zool. v. 1904, p. 50'. 



Depth of body 3| to 3| in the length, length of head 3jf to 4. Snout obtuse ; diameter of eye 3 i to 3| in the 

 length of head. Dorsal 10, with 8 branched rays. An;d 8. 50 to 55 scales in a longitudinal series, 



8 between lateral line and base of ventral. A dark lateral stripe ; males dark with pale vertical bars. 



Hah. South-western Texas and Northern Mexico : 



Rio Pecos 1 and Brownsville ^ in Texas ; Rio Casas Grandes -^ Rio Santa Maria '-\ 

 Rio Conchos^ [Meek) and Mihaca^ in Chihuahua. 



Here described from six specimens, measuring up to GO mm. in total length. 



18. COCHLOGNATECUS, Baird & Girard, 1854. 

 Cochlofjnathus, Jord. & Evcrm. BuU. U.S. Nat. Mus. xlvii. 1896, p. 251. 

 Differs from Fimephales especially in the structure of the jaws, each of whicli is provided with a hard cutting- 



