Parapolystoma johnstoni n. sp. from Litoria nyakalensis (Amphibia) in Australia and taxonomic considerations on the Diplorchiinae (Monogenea).

Parapolystoma johnstoni n. sp. is described from Litoria nyakalensis from northern Queensland. Parapolystoma bulliense is recorded from a new host, Litoria pearsoniana. The pattern of the ciliated cell on the oncomiracidium of P. bulliense is described. The subfamily diagnosis of the Diplorchiinae is amended to include the species of Diplorchis, Neodiplorchis, Parapolystoma, and Pseudodiplorchis.