Taxonomic clarification of three taxa of Iberian geomitrids, Helix montserratensis Hidalgo, 1870 and subspecies (Gastropoda, Pulmonata), based on morpho-anatomical data

Helix montserratensis (currently Xerocrassa montserratensis) is an Iberian geomitrid described by Hidalgo in 1870 from Montserrat (Barcelona, Spain). Two very similar taxa were described as varieties of this taxon based only on conchological characters: Helix montserratensis betulonensis and a less known taxon, Helix montserratensis delicatula. These varieties, especially betulonensis, were considered for a long time as subspecies of X. montserratensis, although some authors upgraded them to the rank of species based on anatomical data of the reproductive system in a few specimens. We review the type specimens and other samples of the three taxa collected at several localities where the three referred taxa are considered present. The morpho-anatomical characteristics of the shell and the reproductive system were studied in detail. The results allow us to clarify the taxonomic status of X. betulonensis and X. m. delicatula as X. montserratensis, indicating they should be considered junior synonyms of this species. Finally, the shell is redescribed and a map is provided showing the geographical distribution of X. montserratensis.