GENUS DELTISTES SEALE 



This genus is close to Chasmistes, from which it differs 

 chiefly in the structure of the gillrakers, the very long, slender 

 head, the small horizontal mouth, and the thicker lips. The 

 gillrakers are broad and shaped like the Greek letter A (delta) 

 and their edges are unarmed and entire; lower pharyngeals 

 weak, with numerous small teeth. 



The single known species is the Lost River sucker (D. luxatus), 

 which is the most important food-fish of the Klamath Lakes 

 region. It is apparently resident during most of the year in the 

 deeper waters of Upper Klamath and Tule lakes, running up 

 the rivers in March and April in incredible numbers, the height 

 of the run varying from year to year according to the condition 

 of the streams. The Lost River fish are the most highly prized, 

 and are said to be much fatter and of finer flavour than those 

 ascending the tributaries of Upper Klamath Lake. 



This species reaches the largest size of any of the Klamath 

 Lake suckers, examples over 3 feet in length and weighing 

 several pounds having been examined. It is of vast importance 

 to the Klamath Indians, who, during the spring run, catch it in 

 immense numbers and cure it for winter use. 



An attempt has been made to preserve the meat in cans, 

 but apparently without success. Oil has been extracted from the 

 heads and entrails, said to be worth 6oc. to 85C. per gallon. 



Head 4; depth 4*; snout 2f in head; D. 12; A. 7; scales 



12-76 to 81-9. Body elongate; head very long and slender, the 



snout and cheek especially long; mouth inclined upward at an 



angle of about 35; fontanelle large; premaxillary spines forming a 



decided hump on snout near its tip. 



GENUS XYRAUCHEN EIGENMANN & KIRSCH 



The characters of this genus agree in all respects with those 

 of Catostomus except that behind the occiput is a sharp-edged 

 hump produced by the singularly developed interneural bones, 

 giving the adult fish a very grotesque appearance. 



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