The Tswam 



Lake, which is a close rival of Utah Lake for the honour of being the 

 "greatest sucker pond in the world," 



It is the most abundant species of the genus in the Klamath 

 Lakes. It reaches a length of 15 to 18 inches and is of great value to 

 the Indians, by whom it is known as " Kahptu." 



From all other species of the genus, except C. brevirostris and 

 C. copei, it is distinguished by its small scales (14 or 15-76 to 8^-11), 

 and from C. brevirostris it differs in the deeper head, larger man- 

 dible, more oblique mouth, and by the prominent hump on the snout; 

 mouth inclined at an angle of 40°. Colour, dark above, whitish or 

 silvery below, the two colours separated along a definite line travers- 

 ing the side midway between lateral line and insertion of 

 ventrals. 



Tswam 



Chasmistes copei Evermann & Meek 



This is still another species of Chasmistes, inhabiting the Klamath 

 Lakes. It closely resembles C. stomias, but may be distinguished 

 from that species by its larger head, larger, more oblique mouth, less 

 prominent snout, and very small fins. 



This sucker reaches a length of 16 or 18 inches and is used as 

 food by the Klamath Indians. The Indian name is "Tswam." 



Head 3I; depth 4; eye 6|; snout 2|; D. 10; A. 7; scales 

 13-80-12. Head very large, cheek very deep; body stout, back 

 scarcely elevated. Colour, upper parts dark olivaceous; under parts 

 whitish; a dark spot in upper part of axil; dorsal and caudal dark; 

 pectoral dark on inner surface; ventrals and anal plain. 



S'J 



