Taxonomy of Heterocotyle dasyatis n. comb. (syn. Diploheterocotyla dasyatis) (Monogenea: Monocotylidae).

The monotypic genus Diploheteocotyla Yamaguti, 1965, parasitic on the gills of a dasyatidid ray collected off Hawaii, is synonymized with Heterocotyle Scott, 1904. Its type species, D. dasyatis Yamaguti, 1965, is redescribed, illustrated, and transferred to Heterocotyle as H. dasyatis (Yamaguti, 1965) n. comb. Heterocotyle dasyatis is distinguished from the 9 known species of the genus by the morphology of the male copulatory organ, by the accessory piece, which is composed of 10 sclerotized strands, and by the presence of a complex sclerite in the proximal portion of the vagina. The apparent presence of spermatophores is recorded for the first time in this genus.