Myriopoda

Myriopoda (Gr., 'myriad-footed'), a class of terrestrial Arthropods with numerous and very uniform segments. The head is distinct and bears a pair of antennæ, while mandibles and maxillæ form the true mouth-appendages. The legs themselves have six or seven joints, and end in a claw. Respiration is discharged by air-tubes or tracheæ. The class includes two orders, which differ considerably: the Centipedes (Chilopoda), with flattened body, a pair of legs on each ring, the second pair behind the mouth with powerful poison-claws; and the Millipedes (Chilognatha), with cylindrical body, and two pairs of legs on most of the rings. The Centipedes are carnivorous, and their venomous 'bite' is sometimes dangerous; the Millipedes are destructively vegetarian, but otherwise harmless. Generally they avoid the light, and live in the ground, under stones, among moss, under bark, or in similar hidden habitats. A few have a quite ancestral-like simplicity of structure. Fossil forms appear in Carboniferous strata. See CENTIPEDE.