Cetorhinicola n. g., Shirleyrhynchus n. g. and Stragulorhynchus n. g., three new genera of trypanorhynch cestodes from elasmobranchs in Australian waters

Three new genera of trypanorhynch cestodes are described from Australian elasmobranchs: Cetorhinicola acanthocapax n. g., n. sp. from Cetorhinus maximus (Gunner, 1765), with four bothridia joined by avelum, a typical heteroacanthous armature with the ends of the hook rows not meeting on the external surface, and enlarged hooks on the base of the tentacle; Shirleyrhynchus butlerae n. g., n. sp., from Dasyatis fluviorum Ogilby, 1908 and D. sephen (Forsskal, 1775), with four bothridia, typical heteroacanthous armature, enlarged basal hooks, testes in linear rows, and lacking seminal vesicles; Stragulorhynchus orectologi n. g., n. sp., from Orectolobus tentaculatus (Peters, 1864) (type-host), O. maculatus (Bonnaterre, 1788) and O. ornatus (de Vis, 1882), with four bothridia, poeciloacanthous armature, with a band of hooklets on the external surface of the tentacle, external seminal vesicle, hermaphroditic duct, accessory seminal vesicle and post-ovarian testes. None of the new genera is readily accommodated by the existing classification of the Trypanorhyncha: the first two genera are tentatively allocated to the Gilquiniidae and the last to the Gymnorhynchidae.