This order comprises the vegetable-eating Millepedes (lulidae), the Galleyworms (Polydesmus), and other allied forms. The order is characterised by the great number of legs - each segment, except the five or six anterior ones, bearing two pairs - by the composition of the antennae out of six or seven joints; and by the structure of the masticating organs, which consist of a pair of mandibles without palps, covered by a lower lip, composed of the confluent maxillae. The generative apertures are placed in the anterior portion of the body.

Fig. 171.   Millepede (Iulus).

Fig. 171. - Millepede (Iulus).

In the common Millepede (lulus) the body is composed of from forty to fifty segments, each of which bears two pairs of minute, thread-like legs. The Iuli of this country are of small size, but an American species attains a length of more than half a foot. The Glomeridae, or "Pill-Millepedes," live under stones, and have the power of rolling themselves up into a ball.