Morphology of the head of Amphineurus (Rhamphoneurus) (male). A Head of A. (R.) chiloeanus (lateral view); B Mouthparts of A. (R.) nullus (dorsal view). — Abbreviations: cv, cervical sclerites; hph, hypopharynx; lbl, labella; lbr, labrum; plp, palpus; rst, rostrum; t r, tip rostrum; vt, vertex.