The identity of Hauffenia (Neohoratia) gasulli Boeters, in Gasull, 1981, type material, with shell topotypes and live specimens collected in neighbouring localities, has been established on the basis of shell characters (statistical analysis DFA and Anova). Anatomical studies confirmed its allocation to a new genus, Tarraconia, which is only known from the Iberian Peninsula. We present histological data to demonstrate the lack of a seminal receptacle, its function having being transferred to a wide part of the proximal renal oviduct. This character, together with a well-defined data set, including lack of a suboesophageal connective and a gastric caecum, penis size and shape, and a well-developed bursa copulatrix fully protruding from the albumen gland characterise the new genus. Tarraconia rolani, n. sp., is also described. The function of the seminal receptacle having moved to a different part of the genital system, found for the first time among Iberian hydrobiids, has occurred several times in the Hydrobioidea evolution in different families, such as Hydrobiidae, Pyrgulidae, Pomatiopsidae, showing it not to be a useful character to justify suprageneric-level taxa. Detailed anatomical studies are necessary to unravel the obscure phytogenetic relationships of this group of gastropods, which, due to their small size, yield very few diagnostic characters and a high degree of convergence.
