1948 CX. x. 61 The distinctive feature relating to the feeding apparatus of the Acarina is the presence of a discrete head structure carrying the mouth parts, known as the capitulum, capitellum, or gnathosoma.
1959 T. E. Hughes x. 135 The gnathosoma is movable on the rest of the body and is well sclerotized... The gnathosomal roof consists of the fused tergites of the segments concerned.