At present, the collection of the Zoological Institute contains 29 type specimens of 23 species of pelagic nemerteans from the orders Pelagica and Cratenemertea. The types of four species (Pelagonemertes laticauda Korotkevitsch, 1955, P. oviporus Korotkevitsch, 1955, Obnemertes maximovi Korotkevitsch, 1960 and O. ramosa Korotkevitsch, 1960) have not been found. The lectotype for Mesarmaueria pellucida Korotkevitsch, 1955 is designated. The genus Nemertobus Chernyshev, 1992 is synonymized with Obnemertes Prudhoe, 1963. Nectonemertes compacta Korotkevitsch, 1964 and Pelagonemertes parvula Korotkevitsch, 1964 are transferred to Chuniella Brinkmann, 1917 and Balaenanemertes Burger, 1909, respectively.