“…Because of the great variability in the diagnostic characters used for adults (Bakke, Dr. W. Junk b.v. Publishers -The Hague, The Netherlands 1978c), scanning electron microscope (SEM) study was made of the surface topography of adults, experimentally reared from known sporocysts, to determine if this would reveal additional characters for L. paradoxum. These and previous results (Bakke, 1976a(Bakke, , b, 1978b indicate that the classification based on adults and presented by Kagan (1950Kagan ( , 1951Kagan ( , 1952b (which also needs revision), should be replaced by a system based primarily on larval similarities and differences. In the present paper a new classification is proposed based on the author's data and on information on the larvae available in the literature.…”