Los tipos de Neritina valentina Graells, 1846 redescubiertos

The genus Theodoxus is distributed in lakes, rivers and estuaries of Europe, Southwest Asia and North Africa, but its taxonomy is still incompletely understood. Theodoxus valentinus (Graells, 1846) is an endemic Iberian species with a very localized distribution and with a very particular shell shape, practically extinct and listed as critically endangered by the IUCN. This article reveals the recent discovery in the collection of the Museo Nacional de Ciencias Naturales of Madrid (Spain) of the type material of Neritina valentina Graells, 1846, and other specimens of this species, coming from other collections, are also studie