A new genus and a new species of hydrobiid snail (Mollusca : Gastropoda : Hydrobiidae) from eastern Spain

The identity of Hauffenia (Neohoratia) gasulli Boeters, in Gasull, 1981, ty pe material, with shell topotypes and live specimens collected in neighbour ing localities, has been established on the basis of shell characters (stat istical analysis DFA and Anova). Anatomical studies confirmed its allocatio n to a new genus, Tarraconia, which is only known from the Iberian Peninsul a. We present histological data to demonstrate the lack of a seminal recept acle, its function having being transferred to a wide part of the proximal renal oviduct. This character, together with a well-defined data set, inclu ding lack of a suboesophageal connective and a gastric caecum, penis size a nd shape, and a well-developed bursa copulatrix fully protruding from the a lbumen 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 use ful character to justify suprageneric-level taxa. Detailed anatomical studi es are necessary to unravel the obscure phytogenetic relationships of this group of gastropods, which, due to their small size, yield very few diagnos tic characters and a high degree of convergence.