Series Ostariophysi 393 
body, and jet-black coloration, which comes up the smaller 
rivers tributary to the Mississippi and Ohio in large numbers 
Fic. 806 —Common Sucker, Catostomus commersoni (Le Sueur). Ecorse, Mich. 
in the spring. Most of the other suckers belong to the genera 
Catostomus and Moxostoma, the latter with the large-toothed 
Placopharynx being known, from the red color of the fins, as 
Fic. 307. —California Sucker, Catostomus occidentalis Agassiz. (Photograph by 
Cloudsley Rutter.) 
red-horse, the former as sucker. Some of the species are very 
widely distributed, two of them (Catostomus commersom, Ert- 
myzon sucetta) being found in almost every stream east of the 
Rocky Mountains and Catostomus catostomus throughout Canada 
to the Arctic Sea. The most peculiar of the suckers in appear- 
ance is the harelip sucker (Quassilabia lacera) of the Western 
rivers. Very singular in form is the hump-back or razor-back 
sucker of the Colorado, Xyrauchen cypho. 
Fossil Cyprinide.—Fossil Cyprinide, closely related to exist- 
ing forms, are found in abundance in fresh-water deposits of the 
Tertiary, but rarely if ever earlier than the Miocene. Cyprinus 
