New acanthodrilid species from Madagascar (Clitellata, Acanthodrilidae)

During collecting trips to Madagascar in the last decade several Acanthodrilidae sensu lato species were collected. The newly acquired material expresses high variability of the excretory system containing meroic, holoic vesiculate and holoic avesiculate species. The possible relationships of the Malagasy acanthodrilids is discussed and five species; Acanthodrilus hesperus, Eodriloides metandricus, Howascolex proprioporus, Howascolex vohimanus and Vazimbascolex alaotranus spp. n. are described. Vazimbascolex gen. n. represents also a new genus to science. The holoic avesiculate Acanthodrilus majungianus Michaelsen, 1897 and A. voeltzkowi Michaelsen, 1897 are conditionally transferred to the South African genus Eodriloides Zicsi, 1998; Eodrilus dauphinianus Michaelsen, 1910 and Microscolex (Notiodrilus) hyalochaeta Michaelsen, 1907 to Howascolex Michaelsen, 1901.