AMIURUS.—LEPTOPS. 141 
9. Amiurus dugesi. 
Amiurus dugesi, Bean, Proc. U.S. Nat. Mus. 1879, p. 804’; Jord. & Everm. Bull. U.S. Nat. Mus. 
xlvil. 1896, p. 13887; Meek, Publ. Columbian Mus., Zool. v. 1904, p. 15°. 
Hab. Mexico, Rio Lerma System ! 2 3, 
I have examined a number of specimens in the British Museum from Lake Chapala 
(Jordan, Meck) measuring up to 200 mm. in total length. A specimen from Salamanca 
(Woolman) appears to belong to the same species, but has the dorsal and pectoral 
spines shorter, less than 4 the length of head. 
10. Amiurus balsanus. 
Istlarius balsanus, Jord. & Snyder, Bull. U.S. Fish. Comm. xix. 1899, p. 118 (1900)'; Jord. & 
Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 3138° ; Meek, Publ. Columbian Mus., Zool. v. 
1904, p. 17, fig. 2°. 
Hab. Mexico, Rio Balsas ! 2 3, 
The premaxillary band of teeth has a slight posterior projection on each side, but 
this is scarcely sufficient justification for placing this species in a different genus from 
A. dugesti, to which it is closely allied. I have examined three specimens (Jordan, 
Meek), the largest 180 mm. in total length. The species attains a length of 900 mm. © 
11. Amiurus natalis. 
Amiurus natalis (Le Sueur), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 139’; Meek, 
Publ. Columbian Mus., Zool. v. 1904, p. 16°. 
Hab. Nortu America, Great Lakes to the Rio Grande! 2. 
8. LEPTOPS, Rafinesque, 1820. 
Leptops, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 142. 
Premaxillary band of teeth with a well-developed pointed posterior extension on each side; dorsal fin with 
a spine and 7 branched rays; in other respects similar to Amzurus. 
A single species from North America and Northern Mexico. 
1. Leptops olivaris. 
Leptops olivaris (Rafinesque), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 143+; Meek, 
Publ. Columbian Mus., Zool. v. 1904, p. 18°. 
Body slender ; head depressed ; lower jaw a little projecting. DorsalI 7. Anal 13-16, Caudal truncate. 
Pectoral spine with the inner edge serrated and with the outer edge roughened or serrated. Yellowish, 
marbled with brownish. 
Hab. Norta America, Mississippi System and Southern United States! ?.—MExico, 
Chihuahua ? . 
This species is an important food-fish, and is said to attain a weight of fifty to 
seventy-five pounds. 
