Abstract
Summary: A comparative study has been made of the Pseudophyllidean cestodes harboured by Pinnipeds, mainly from the Northern Hemisphere. Thirty species of this group of cestodes have been recorded in the literature, and as a result of the present study these may be divided into the following:Valid species: Diphyllobothrium cordatum (Leuckart, 1868); D. elegans (Krabbe, 1865); D. glaciale (Cholodkovsky, 1915); D. hians (Diesing, 1850); D. lanceolatum (Krabbe, 1865); D. scoticum (Rennie & Reid, 1912); Diplogonoporus tetrapterus (v. Siebold, 1848); D. fasciatus (Krabbe, 1865); and Pyramicocephalus phocarum (Fabricius, 1780).