Charopid snails of Mounts Mahermana, Ilapiry, and Vasiha, southeastern Madagascar, with description of a new genus and with conservation statuses of nine species

Quantitative, replicated altitudinal transects yielded nine charopids, all belonging to the endemic genus Reticulapex gen. nov., which is characterize d by cross-hatched embryonic sculpture; an extremely elongate fertilization pouch-seminal receptacle complex, nearly basal entry of the vas deferens i nto, and nearly apical origin of the penial retractor muscle from, the epip hallus; and deposition of a spiral spermatophore on the mate's penis. Reticulapex gen. nov. represents the fifth known independent evolution of e xternal sperm exchange within the Stylommatophora. At least some other char opids have internal sperm exchange. Descriptions are given of Reticulapex g en. nov. apexfortis sp. nov., R. compactus sp. nov., R. fischerpiettei sp. nov., R. flammulatus sp, nov., R. lucidus sp. nov., R. scaber sp. nov., R. subangulatus sp. nov., R. ulrichi (Fischer-Piette, Blanc, Blanc & Salvat, 1 994) comb. nov., and R. villosus sp. nov. Description of Reticulapex gen. nov. includes the additional new combinatio ns R. choutardi (Fischer-Piette, Blanc, Blanc & Salvat, 1994) comb. nov., R . druggi (Fischer-Piette, Blanc, Blanc & Salvat, 1994) comb, nov., R, haran anae (Emberton, 1994) comb. nov., R. intridi (Fischer-Piette, Blanc, Blanc & Salvat, 1994) comb, nov., R, talatai (Emberton, 1994) comb. nov., R. vatu vayae (Emberton, 1994) comb. nov., and R. vineti (Fischer-Piette, Blanc, Bl anc & Salvat, 1994) comb. nov. Distributional data allowed evaluation of each of the nine Mahermana-Ilapir y-Vasiha charopid species for its conservation status, applying the latest IUCN criteria. Two species are proposed as Critically Endangered and seven as Endangered.