COCHLOGNATHUS.—COUESIUS. 165 
pete The pharyngeal teeth are more strongly hooked than in Pimephales, and the intestine is 
snorter. 
Two species from Texas and the Rio Grande. 
1. Cochlognathus ornatus., 
Cochlognathus ornatus, Baird & Girard, Proc. Ac. Philad. 1854, p. 1587; Girard, Bull.U.S. & Mex. 
Bound. Surv., Fish. p. 46, t. 25. figs. 12-17 (1859) *; Jord. & Everm. Bull. U.S. Nat. Mus. 
xlvii. 1896, p. 252°. 
Hab. Rio Grande at Brownsville ! 23, 
19. YURIRIA, Jord. & Everm., 1896. 
Yuriria, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 315. 
Body elongate, compressed. Mouth protractile, terminal, oblique; a small barbel at the end of each 
maxillary. Pharyngeal teeth compressed, hooked, in a single series, 4—4. Gill-openings separated by 
a narrow isthmus. Scales large. Dorsal and anal fins short, the former about in the middle of the 
length of the fish; ventral fins 10-rayed. 
A single species from the Rio Lerma System. 
1. Yuriria alta. 
Hudsonius altus, Jord. Proc. U.S. Nat. Mus. 1879, p. 301°. 
Hybopsis altus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 321%, and 1900, fig. 138° ; 
Meek, Publ. Columbian Mus., Zool. v. 1904, p. 81°. 
Depth of body about 4 in the length, length of head 33 to 4. Snout longer than eye, the diameter of which 
is 4} to 5 in the length of head ; interorbital width 3 in the length of head. Dorsal 9, with 7 branched 
rays; origin nearly equidistant from tip of snout and base of caudal; longest ray % to 4 the length of 
head; free edge straight or slightly concave. Anal 9. Pectorals nearly or quite reaching the ventrals, 
which are inserted below the origin of dorsal. 45 to 50 scales in a longitudinal series, 8 to 10 ina 
transverse series from origin of dorsal to lateral line, 4 or 5 between lateral line and base of ventral. 
Lateral line complete, slightly decurved. Caudal peduncle 13 to 2 as long as deep. Silvery, back 
darker ; fins pale. 
Hab. Mexico, Rio Lerma System : 
Aguas Calientes * (Jordan, Meek), Lagos+, Celaya‘ (Meek), Acambaro *, Lago 
de Tupataro !, Salamanca? (Woolman) ; Rio Cuitzeo*; Ojo de Agua, Michoacan 
(Mexico Mus.). 
Here described from several specimens, measuring up to 130 mm. in total length. 
20. COUESIUS, Jord., 1878. 
Couesius, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 323. 
eding genus, but the body less compressed, the barbel not quite terminal, the 
Very similar to the prec 
ales smaller. 
pharyngeal teeth in two series, 2, 4—4, 2, and the se 
Five species from North America, including one from Northern Mexico. 
Y 2 
