The Identity of Inobseratella Lindholm, 1924 and Its Type Species Clausilia lantzi Lindholm, 1924 (Gastropoda: Clausiliidae) from Northeastern Turkey

Inobseratella Lindholm, 1924, and the only included species Clausilia (Inobseratella) lantzi Lindholm, 1924, were described by Lindholm (1924) based on a single specimen as the “first Caucasian species, in which there is no clausilium”. However, Likharev (1962) recognized that there is a broken stalk of a clausilium in the holotype. He placed C. lantzi in the synonymy of Armenica brunnea (Rossmässler, 1839). Nordsieck (1979) obviously doubted this identification and classified Inobseratella as incertae sedis. Although the holotype of C. (Inobseratella) lantzi is available in the Zoological Institute of the Russian Academy of Sciences in St.-Petersburg, the identity of the taxon has not been clarified thus far. Clausilia lantzi was one of the first clausiliid species described from the eastern Pontus Mountains. Several endemic species and genera were described later from this region, which might turn out to be junior synonyms of C. lantzi or Inobseratella. We studied the holotype of C. (Inobseratella) lantzi, figured it for the first time and clarified the identity of C. lantzi and Inobseratella to stabilize the nomenclature.