A revision of the genus Alzoniella Giusti & Bodon, 1984 (Gastropoda, Caenogastropoda, Hydrobiidae) on the Iberian Peninsula and its implications for the systematics of the European hydrobiid fauna

The genus Alzoniella Giusti & Bodon, 1984, is reviewed for the Iberian Peninsula. This revision includes both the nominate subgenus Alzoniella (A.) and A. (Navarriella) Boeters, 2001, as well as the genus Guadiella Boeters, 2003, since its type species, G. andalucensis (Boeters, 1983), was formerly regarded as belonging to Belgrandiella A. J. Wagner, 1928, together with A. cantabrica (Boeters 1983) and A. edmundi (Boeters, 1984), which are now classified in Alzoniella. Most of the newly reported localities enlarge known distribution areas. Various new data on anatomical aspects are presented. Photographs of shells and the protoconchs of nearly all the species discussed are included. Two new species are described and three insufficiently known taxa of Alzoniella are mentioned, but without assigning any specific name.