A REVISION OF MUCETUM DORCHYMONT AND RHOMBOSTERNUM BALFOUR-BROWNE (COLEOPTERA, HYDROPHILIDAE) WITH A PHYLOGENETIC ANALYSIS OF PROTOSTERNINI

The Protosternini genera Mucetum d'Orchymont and Rhombosternum Balfour -Browne, belonging to Sphaeridiinae, are redescribed and redefined. Mu cetum carinatum d'Orchymont, Rhombosternum birmanense Balfour-Browne a nd R. wagneri (Knisch) are redescribed. Four new species of Rhomboster num are described, from Birmania, Indonesia, Philippines and Sarawak. For each species, details are given of male and female genitalia whene ver possible. Four morphometric parameters of Rhombosternum species ar e subjected to univariate analysis. A cladistic analysis of all known species of Protosternini, including Protosternum Sharp, is performed. Morphometrically continuous characters are considered to be irrelevant to the phylogenetic analysis. Some biogeographic interpretations are briefly discussed. Identification keys are provided for the three Prot osternini genera and for the known species of Rhombosternum, sometimes using quantitative morphometric characters. A List is given of the kn own Protosternini.