AMIUEUS.— LEPTOPS. 141 



9. Amiurus dugesi. 



Amiurus dugesi, Beaa, Proc. U.S. Nat. Mus. 1879^ p. 304'; Jord. & Everm. Bull. U.S. Nat. Mvis. 

 xlvii. 1896, p. 138 ^ ; Meek, Pabl. Columbiau Mus., Zool. v. 1904, p. 15 \ 



Hah. Mexico, Eio Lerma System ^ - ^. 



I have examined a number of specimens in the British Museum from Lake Chapala 

 {Jordan, Meek) 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 ^ 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 \ 



Hob. Mexico, Eio Balsas ^ ^ 3. 



The prsemaxillary 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. dugesii, to which it is closely allied. I have examined three specimens (Jordmi, 

 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 \ 



Hah. North America, Great Lakes to the Rio Grande ^ ^. 



8. LEPTOPS, Eafinesque, 1820. 

 Laptops, Jord. & Everm, Bull. U.S. Nat. Mus. xlvii. 1896, p. 142. 



Prsemaxillary 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 Amiurus. 



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. Dorsal I 7. Anal 13-16. Caudal truncate. 

 Pectoral spine with the inner edge serrated and with the outer edge roughened or serrated. YeUowish, 

 marbled with brownish. 



Hah. North 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. 



