Cephalic anatomy of Sinentomon erythranum Yin (Protura : Sinentomidae)

Abstract The structure of the head capsule, endoskeletal structures, oral folds, mouthparts, foregut, maxillary and labial glands, and the central nervous system of the Chinese proturan Sinentomon erythranum Yin (Protura : Sinentomidae) have been described. The most significant features are the unusual thickness of the cuticle with numerous serrated lines, the reduction of sutures and the absence of linea ventralis, the simplification of gnathal pieces, and the reduction of the musculature. A comparison with other Protura and Apterygota leads to some morphological and phylogenetical interpretations of the cephalic structures, in particular those concerning the entotrophy.