A new species of the genus Archicotylus (Tricladida, Dendrocoelidae) from Lake Baikal

The Baikal turbellarian fauna is abundant and diverse. The planarians are one of the most interesting groups of this fauna. The genus Archicotylus Korotneff 1912 (Turbellaria, Tricladida, Paludicola) is endemic for Lake Baikal. An illustrated description of two species of the genus Archicotylus (Archicotylus stringulatus (Korotneff 1912) and Archicotylus elegans sp. n.) is given. Archicotylus elegans sp. n. is described as a new member of the Lake Baikal fauna. A detailed description of the reproductive system, pharynx, and musculo-cutaneous sac is provided