ALGANSEA.—LEUCISCUS. 155 
L. Patzcuaro (Mexico Mus., Meek). These evidently correspond to Steindachner’s 
A. lacustris and A. tarascorum. Meek gives 85 to 100 scales in a longitudinal series 
for A. lacustris, but my lower counts agree with those of Steindachner. I have 
examined the type of 4. dugesi in the U.S. National Museum at Washington. I[ 
count 84 scales in a longitudinal series, 18 between dorsal fin and lateral line, 14 from 
lateral line to root of ventral fin. 
A. rubescens is said to differ from A. dugest in the more numerous gill-rakers, 22 or 
23 on the first arch ; in the specimens described above I count 19 to 22 (4-5+4-15-17). 
9. PTYCHOCHEILUS, Agass., 1855. 
Ptychocheilus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 224. 
This genus differs from Zeuciscus in the large subterminal horizontal mouth 
extending to below the eye and in the subconical pharyngeal teeth set wide apart on 
the long, slender, lower pharyngeal bones. It comprises. three species, large fishes 
from the Pacific Coast streams of the United States and Northern Mexico. 
1. Ptychocheilus lucius, Girard, 1856. 
Ptychocheilus lucius, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 224; Meek, Publ. 
Columbian Mus., Zool. v. 1904, p. 52. 
Hab. Colorado River and Northern Sonora. 
This species is said to reach a length of five feet and a weight of eighty pounds. 
10. LEUCISCUS, Cuv., 1817. 
Gila (Baird & Girard) and Leuciscus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, pp. 226 
and 228. 
Body ovate or elongate, more or less compressed. Mouth protractile, terminal or subterminal, small or 
moderate, usually more or less oblique; no barbels. Pharyngeal teeth compressed, hooked, in two 
series, 1-2, 4-6—6-4, 1-2. Dorsal fin short; anal short or of moderate length. 
A large number of species from Europe, Asia, and North America. 
Synopsis of the Mexican Species. 
85 to 90 scales in a longitudinal series. . ©. . . . ee. ew we Od elegans. 
60 to 75 scales in a longitudinal series. 2. 2. 1 1 ee ee ee ee wR nigrescens. 
1. Leuciscus elegans. 
Gila elegans, Baird & Girard, Proc. Ac. Philad. 18538, p. 869°; Jord. & Everm. Bull. U.S. Nat. 
Mus. xlvii. 1896, p. 226°; Meek, Publ. Columbian Mus., Zool. v. 1904, p. 53°. 
? Gila minace, Meek, t. c. p. 54, fig. 11°. 
BIOL. CENTR.-AMER., Pisces, November 1907. xX 
