First Report of a Live Population of Bulgarica fritillaria (Frivaldszky, 1835) (Gastropoda: Pulmonata: Clausiliidae and its Relationships with the Species of the Bulgarica varnensis Species-group from Bulgaria

The paper reports the first live population of Bulgarica fritillaria (Frivaldszky, 1835), which has been discovered at Bessapara Hills near the village of Kapitan Dimitrievo in Bulgaria. The morphology of the species is redescribed on the basis of the newly-discovered population and its morphological differences from Bulgarica varnensis (L. Pfeiffer, 1848) are discussed. Bulgarica fritillaria prefers clamp habitats, rich in detritus and overgrown with vegetation, mostly along river banks, which differs it from B. yarnensis. The other three taxa of the Bulgarica varnensis species-group, previously considered as subspecies of B. varnensis, i.e. B. pseudofraudigera described initially as B. v. pseudofraudigera Nordsieck, 1973, B. v. gabrovnitsana lrikov, 2006 and B. v. trimontsiana Irikov, 2006, are recognised as full species and their rank is elevated. Bulgarica fritillaria, B. gabrovnitsana, B. trimontsiana and B. pseudofraudigera are endemic species for the fauna of Bulgaria.