A class, or subclass, of arthropods, related to the hexapod insects, from which they differ in having the body made up of numerous similar segments, nearly all of which bear true jointed legs. They have one pair of antennæ, three pairs of mouth organs, and numerous tracheæ, similar to those of true insects. The larvæ, when first hatched, often have but three pairs of legs. See Centiped
. [1913 Webster
" The existing Myriapoda are divided into three orders: Chilopoda, Chilognatha or Diplopoda, and Pauropoda (see these words in the Vocabulary). Large fossil species (very different from any living forms) are found in the Carboniferous formation."