ALGANSEA. — LEUCISCUS. 153 



L. Patzcuaro (Mexico Mas., MeeJc). These evidently correspond to Steindachner's 

 A. lacustris and A. farascorum. Meek gives 85 to 1 00 scales in a longitudinal series 

 for A. lacustris, but my lower counts agree with those of Steindachner. I have 

 examined the type of At. dugesi in the U.S. National Museum at Washington. .1 

 count 84 scales in a longitudinal series, 18 between dorsal fin and lateral line, 14 from 

 lateral line to root of ventral fin. 



A. ruhesceiis is said to differ from A. dugesi 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 + 15-17). 



9. PTYCHOCHEILUS, Agass., 1855. 

 Ptychocheilus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 2.2i. 



This genus differs from Leuciscus 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. 



Hah. Colorado Hiver 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 ; uo barbels. Pharyngeal teeth compressed, hooked, in t^v 

 series, 1-2, 4-G — 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. 



8.5 to 90 scales in a longitudinal series 1. ehgans. 



60 to 75 scales in a longitudinal series 2. nigrcsceus. 



1. Leuciscus elegans. 



Gila elegans, Baird & Girard, Proc. Ac. Philad. 1853, p. 369 ^ Jord. & Everm. Bull. U.S. Nat. 



Mus. xlvii. 1896, p. 226 = ; Meek, Publ. Columbian Mus., Zool. v. 1904, p. 53 \ 

 ? Gila minacm. Meek, t. c. p. 54, fig. 11 ^ 



BIOL. CENTR.-AMER., Pisces, November 1907. X 



