Contribution to the knowledge of the Bulgarian species of the genus Vitrea (Gastropoda, Pristilomatidae) with the description of a new species

A new species of genus Vitrea is described: Vitrea ulrichi sp. n. is the eleventh species within the genus found in Bulgaria, and the largest representative of the Bulgarian Vitrea. Some critical notes on the taxonomy of the species V. bulgarica and V. sturanyi are presented. A key is provided for the determination of the species of Vitrea found in the country