Hydraenidae of Madagascar (Insecta: Coleoptera) Author Perkins, Philip D. text Zootaxa 2017 2017-11-03 4342 1 1 264 journal article 31639 10.11646/zootaxa.4342.1.1 15799d2a-1968-4874-8100-452597d4e26b 1175-5326 1041066 2ACD54D2-3487-432D-9323-EEC131FE2E64 Hydraena ( Monomadraena ) , new subgenus Type Species: Hydraena ( Monomadraena ) tibiodentipes new species This new subgenus comprises 45 species, which are placed in six species groups. Two of these species, H. impressicollis and H. pentarubra , were included in the molecular phylogeny of Trizzino et al. (2012) , and were found to be located near the base of Hydraena (see Fig. 344 ). Paratypes of several of the species described herein have been retained in 100% ethanol, so future DNA sequence studies will be possible, to give a more complete picture of the basal groups of Hydraena . Diagnosis. In addition to the usual diagnostic characters of Hydraena , with the following combination of characters: head with genae raised, with a posterior ridge, usually interrupted in midline; metaventrite with an anteromedian carina that attains the anterior margin of the plaques, frequently joining the plaques, together forming an inverted Y-shape; males with modified mesotibiae, having a row of strong spines along the inner margin (e.g., Fig. 57 ); and the aedeagus having only one paramere, on the right side, which is long and originates near the basal orifice. Etymology. Named in reference to the single paramere, the geographical distribution ( Madagascar ), and relationship to Hydraena .