Remarks on the new earthworm taxa described by Aladesida and Owa in 2015 from Nigeria (Clitellata: Megadrili)

The earthworm fauna of tropical Africa is clearly understudied. This is mainly due to the lack of local earthworm researchers. Nigeria is an exception in this regard with an excellent earthworm researcher A.O. Segun and his successor S.O. Owa describing some 30 earthworm species belonging to the family Eudrilidae. Recently, Aladesida & Ova (2015) published descriptions of four new earthworm genera and species; Adodrilus stephana (Megascolecidae), Ekitidrilus alabataensis, Paranematogenia eyinwaensis (Ocnerodrilidae), and Imekodrilus hexagastricus (Moniligastridae). Examining the type material of the new taxa deposited in the Natural History Museum, London revealed that Adodrilus stephana Aladesida & Ova, 2015 is a synonym of Gordiodrilus robustus Beddard, 1892, Ekitidrilus alabataensis Aladesida & Ova, 2015 represents a nomen nudum. Due to the juvenile state of the types, the names Imekodrilus hexagastricus Aladesida & Ova, 2015 represent a nomen dubium in the family Ocnerodrilidae and Paranematogenia eyinwaensis a nomen dubium in the family Eudrilidae. To prevent further nomenclatural problems, lectotypes for Adodrilus stephana and Paranematogenia eyinwaensis were designated.