486 FISHERIES OF THE UNITED STATES. [100] 



Genus PLATYGOBIO Gill. 



136. PlatygoMo gracilis (Rich.) Gill & Jordan. Flat-headed 



Chub. 

 Rocky Mountain region from the Kansas and Yellow- 

 stone Rivers to the Saskatchewan; abundant (Jordan 

 & Gilbert). 

 Maximum length of specimens observed, 12 inches. 

 20300. Northern Pacific Railroad Survey. Dr. Suckley. 



Genus SEMOTILUS Rafinesque. 

 Subgenus Semotilits Rafinesque. 



137. Semotilus corpora lis (Mitch.) Putnam. Chub; Horned 



Dace; Little Fall-fish; Corporaalen. 

 United States from Massachusetts southward to Georgia 



and west to Missouri ; not plentiful in Maryland (Uhler 



& Lugger), but elsewhere generally abundant. 

 It sometimes reaches 4 pounds in weight, and is a fair 



food-fish (Cope). The maximum length is said to be 



12 inches. 

 9154. Wisconsin. Prof. S. F. Baird. 



Genus POGOMCHTHYS Girard. 



138. Pogonich thy s macrolepidotiis (Ayres) Jordan. Split- 



tail. 



Pogonichthys inccquilobus B. & G., I'roc. Acad. Nat. Sci., Pliila., 1854, p. 

 136. 



Rivers of California. 



The split-tail is "singularly distinguished from our 

 other Cyprinidw by the great development of the 

 upper lobe of the caudal and its rudimentary rays" 

 (Jordan & Gilbert). Our largest examples are 12 

 inches long. The species is used for food. 



12967. Mare Island, California. Dr. T. H. Streets. 



Genus MYLOCHILUS Agassiz. 



139. Hylochilus caurimis (Rich.) Girard. Columbia Chub. 



Cyprinus (Leuciscus) caurinus Rich., F. B. — A., iii, 1836, p. 304. 



Streams chiefly west of the Cascade range, from Cali- 

 fornia to British Columbia, often entering the sea ; 

 abundant (Jordan & Gilbert). 



This chub reaches a length of 12 inches; it is a food- 

 fish. 

 27271. Puget Sound. Prof. D. S. Jordan. 



