I]\"TEODUCTIOX. 



xxui 



The other Catostoininas have the dorsal fin short. Two of the genera are only found 

 west of the Rocky Mountains, viz. Cliasmistes (4 species) and Xijrauchen (2 species). 

 One species of Xyixcuchen is recorded from Northern Sonora. Catostomus comprises 

 one species from Eastern Siberia and about twenty-five from North America, chiefly 

 in the Rocky Mountain region. Two species occur in Mexico, one from Sonora and 

 one from tlie Rio Grande. Moxostoma includes twenty species from the United States 

 east of the Rocky Mountains, from the Great Lakes to the Rio Grande ; in Mexico 



DlSTKIBUTION OF CaTOSTOMINJS. 



one species is found in the Lerma System and another in the Rio Mascota, a small 

 Pacific coast stream to the south of the Rio Grande de Santiago. Four monotypic 

 genera allied to Moxostoma from the eastern part of the United States complete the 

 count of the Catostominse. 



The Cyprininse comprise more than 1000 species from all parts of the world except 

 the extreme north and the Neotropical and Australian regions. Less than 200 species 

 are known from Africa, and most of these belong to Lidian genera; they are absent 

 from Madagascar. The Indian Region is the richest in genera and species and the 

 most generalized types occur there ; fossil Cyprinidge are found in Tertiary deposits of 

 uncertain age in Sumatra. In the Palsearctic Region the Cyprininae are an important 



