Tortella nitida (Lindb.) Broth. is newly reported for the Russian part of the Caucasus region. Descriptions, illustrations, distinctions, ecology and distributional pattern are given for this species and for T. bambergeri (Schimp.) Broth. and T. flavovirens (Bruch) Broth. recently found in a coastal area of the Black Sea. The identity of T. brotheri (Lindb.) Broth. is discussed. Seven species of Tortella are currently known in the Russian part of the Caucasus: T. alpicola Dixon, T. bambergeri, T. flavovirens, T. fragilis (Hook. & Wilson) Limpr., T. inclinata (R. Hedw.) Limpr., T. nitida and T. tortuosa (Hedw.) Limpr.. A key for identification of these species is provided.