(b) The paired claws on the ends of the parapodia and the fanglike modifications of these on the first post-oral appendages (mandibles) are the only hard chitinous portions of the integument.
(b) Claws and fangs are developed on the branches or rami of the parapodia, not on the end of the axis or corm.
(Compare the definition of the class Chilopoda.) The movement of the legs in Diplopoda is like that of those of Peripatus, of the Phyllopod Crustacea, and of the parapodia of Chaetopoda, symmetrical and identical on the two sides of the body.
Without parapodial jaws; without the addition of originally post-oral somites to the prae-oral region, which is a simple prostomial lobe of the first somite; the first somite is perforated by the mouth and its parapodia are not modified as jaws.
The mandibular parapodia may be supposed during the successive stages of this history to have had, from the first, well-developed rami (one or two) of a palp-like form, so that the change required when the mouth passed away from them would merely consist in the suppression of the gnathobase.