Australian Marsh Beetles (Coleoptera: Scirtidae). 9. The relations of Australasian Ypsiloncyphon species to their Asian congeners, additions, mainly to Petrocyphon and Prionocyphon, and a key to Australian genera of Scirtinae Zwick, Peter Zootaxa 2016 2016-03-02 4085 2 151 198 Zwick, 2016 Zwick 2016 [151,454,1482,1508] Insecta Scirtidae Prionocyphon GBIF Animalia Coleoptera 30 181 Arthropoda species bidentatus sp. nov.   Type material. ♂ Holotype: Crater Lakes N.P., Q., SW of Biggenden, 11.viii.74, H.Frauca (ANIC).  Habitus. BL 2.4 mm, BL/BW ~1.6. HCW equals ~61% of BW. Uniformly light brown, with yellowish pubescence, punctures on dorsal side fine. Antennae not serrate.   Male. Tegmen forming an anteriorly rounded pouch. Parameres triangular, ending in thin sickle-shaped process. Wider, more basal portion of paramere with deep furrow in which slender distal part of genital hook rests. Hook strongly bent, base reaching to centre where it is connected with other parts. Pala a very dark rod which appears fused to wall of tegmen ( Fig. 73). Pala supports wide flat prosthemes caudally, each with two large external teeth. Parameroid thin and straight ( Fig. 74), seeming to originate from mediobasal edge of prostheme and lying on much longer phallic lobe. At base of phallic lobes is a crown of fine folds and plicae, base of lobes slightly sclerotized, along medial edge lobes are transversely annulated.  Female. Unknown.   FIGURES 73−76.Male genitalia of  Prionocyphon bidentatus  n. sp.(73, 74) and  P. serratus  n. sp.(75, 76), overview (73, 75) and detail of penis (74, 76). Abbreviations: gh, genital hook; pa, pala; pd, parameroid; pe, paramere; pl, phallic lobe; pr, prostheme; st, style. Upper and lower scale apply to upper and lower figures, respectively.  Note.Obviously a close relative of  P. serratus, but easily distinguished, especially by the prosthemes. Etymology.The name  bidentatus(bidentate) is a Latin adjective referring to the two large teeth on the outside of the prosthemes.