200 REPORT OF STATE GEOLOGIST. 



Campostoma anomalum (Raf,). 



Stone Roller. 



Jordan and Gilbert, 1882, 8, 149. 



This species can be mistaken for nothing else when the alimentary 

 canal has been examined. The lateral line is complete. Scales, 7-53-8, 

 crowded closely together forward. Dorsal rays, eight ; anal, seven. 

 The color is brownish and olive, often mottled with darker and with a 

 brassy luster. The adult male in the breeding season has most of the 

 dorsal and anal of a bright orange color with a cross-bar of black. At 

 this season, too, the head and much of the body are covered with sharp 

 tubercles. Length, occasionally, eight inches ; usually four or five. 



Distributed from New York westward and southward. Common in 

 every stream in Indiana. Clark and Ohio counties (23, '88, 56) ; 

 Franklin County (5, No. 2, 5); Monroe County (i, '85, 410); White 

 River at Indianapolis (1, '77, 376) ; Maumee and Tippecanoe rivers (1, 

 ' 77, 45) ; Lawrence County (28, '84, 200) ; St. Joseph River, Kankakee 

 River at Plymouth, Eel River at Logansport, Whitley County (4, '88, 

 154-8) ; Vincennes and New Harmony (4., '88, 162) ; White River at 

 Spencer (4, '88, 167) ; Falls of the Ohio {9, 9, 36); Vigo County (16, 

 '94,); Eel River Basin (4, '94,36); Richmond (18, 394); Decatur 

 County, (Shannon). 



This extremely abundant species ascends all our streams, penetrating 

 even to the wayside ditches in spring, in order to deposit its spawn. On 

 account of its small size, it is of no direct economical value. Prof. Forbes 

 found the alimentary canal of the specimens examined to be full of mud 

 and confervoid algse. The mud contained diatoms, larvse of dipterous 

 insects, and protozoa.* 



Genus CHROSOMUS Raf. 



Mouth oblique ; teeth 5-5 or 4-5, with grinding surface. Alimentary 

 canal more than twice the length of the body. Dorsal behind the ven- 

 trals. Scales small. Lateral line incomplete. Pseudobranchiae present. 

 A single species. 



•■Genus OXYGENEUM Forbes. 



Mouth large and terminal. Teeth 5-5, with grinding surface. No pseudobranchije. Lat- 

 eral line complete. Scales small. Dorsal with its origin behind the ventrals. Intestine 

 twice the length of the body or more. 



OXYGENEUM PULVERULENTUM Forbes. 



Forbes,S.F., 1885, W, 135. 



Head small and pointed, four and one-sixth in the length. Depth in length five. Scales 

 of lateral line sixty-three, thirty-one in front of the dorsal. Dorsal eight, anal seven. Color 

 pale, the back and sides with numerous dark dots. Illinois River at Peoria. 



