Any of the freshwater catfishes of North America east of the Rockies belonging to the family Ictaluridæ. Comprising 5 genera and 39 species in North America, the Bullheads are characterized by four barbels, an adipose fin, and a single spine in the dorsal and pectoral fins. Represented in the North Country by the diminutive Tadpole Madtom ( Noturus gyrinus).