Jaws of "Polyxenus lagurus". A, Jaws of second and third pairs. mxl, maxillula; mx.p, palpiform branch of maxilla; mx.lb, lobate process of maxilla; mx.ext, external plate of maxilla perhaps corresponding to the stipes of the gnathochilarium of the Chilognatha; mxxinf, internal plate of maxilla, perhaps corresponding to the mentum and promentum of the gnathochilarium (by Carpenter mx.int is regarded as an appendage posterior to the maxilla); mb, membrane. B, Mandibles of "Polyxenus lagurus"