The Bullhead or Miller's-thumb, is to be found in almost all rivers; it rarely exceeds the length of three inches; its general colour is a yellowish olive, much deeper on the head and upper parts of the back; and the whole body is more or less clouded with small dusky specks; the fins are large and yellowish, and likewise speckled; the head is large and flat, and broader than any part of the body. This fish occasionally swims with great strength and rapidity when in pursuit of its prey, though its general habit is that of lying on the gravel, or under stones, in an apparently inert state. Notwithstanding its disagreeable appearance, it is considered as an eatable fish, and is even regarded as delicate ; the flesh turns of a red or salmon colour on boiling. The Bullhead usually spawns in March and April. This fish, also, is frequently caught when angling for Minnows.