Dues noves espècies del gènere Moitessieria Bourguignat, 1863 (Neotaenioglossa: Rissooidea: Moitessieriidae) de la Font d'en Collell (Albanyà, l'Alt Empordà, Catalunya, Espanya)

—Two new species of the genus Moitessieria Bourguignat, 1863 (Neotaenioglossa: Rissooidea: Moitessieriidae) from Font d’en Collell (Albanyà, l’Alt Empordà, Catalonia, Spain). Two new species, Moitessieria mugae and M. collellensis, are described on the basis of shells collected at Font d’en Collell. The new species are compared to other species from the same genus, using both qualitative and quantitative characters. Many features permit to distinguish the two newly described species from one another. M. mugae, very scarce, displays among others an average-sized shell with a moderate number of whorls, being very slender and conical in shape, with a slightly marked sinule and an obliterated umbilicus, while M. collellensis, much more abundant, displays among others a much greater shell with more whorls, being quite variable in shape but much wider in relation to length, with a very marked sinule and a very wide umbilicus. Both species are distinguished from many species of genus Moitessieria by the sculpture of the teleoconch, being characterized by the presence of spiral crests, which together with the longitudinal ribs form a reticule of quadrangular depressions (more marked in M. collellensis), in spite of displaying spirally-arranged pits. M. massoti and M. simoniana are the closest species to M. mugae, being distinguished by the inclination of the sutures and striation density, among others features. In the case of M. collellensis, M. juvenisanguis is the closest species, being distinguished by smaller dimensions, by a fewer number of whorls, by less inclined sutures, and by a higher striation density. Albeit several different morphotypes can be distinguished in M. collellensis (from quite robust to moderately slender in most cases), the coexistence at the type locality of all these morphotypes, with many intermediate forms, allows us to conclude that these differences in shell form do not have any taxonomic validity.