NEW MONOSTILIFEROUS NEMERTEANS (ENOPLA, MONSTILIFERA) FROM THE SEA OFJAPAN

Three new species of amphiporid nemerteans from Peter the Great Hay ar e described. Amphiporus nadtochiae sp. n. is very similar to A. lactif loreus differing from it by longer anterior diverticula of intestinal caecum and compound cephalic glands. Arctonemertes ussuriensis sp. n. differs from A. thori by the greenish boby after fixation, well develo ped diagonal muscular layer and elongated cerebral organs. In Furugelm ina heteromusculosa gen. et sp. n. large cerebral organs are located u nder the brain, all diverticula of intestinal caecum extend to the bra in, blood system is with extracerebral vessels. New diagnoses of the g enera Amphiporus and Arctonemertes are given. Tagonemertes Correa, 195 7 and Psammamphiporus Gibson, 1989 are considered as junior synonyms o f Amphiporus.