Abstract
Four new species of multi-segmented nassellarians, i.e. Laxtorum(?) jurassicum ISOZAKI & MATSUDA n. sp., L(?). hichisoense I. & M. n. sp., Hsuum hisuikyoense I. & M. n. sp. and H(?). matsuokai I. & M. n. sp., are described from early Jurassic bedded chert containing manganese micronodules at Kamiaso, Mino Belt, Central Japan. The assemblage including these four new species is referable to Hsuum sp. B Assemblage, reported from various localities throughout Japan (e.g. YAO et al., 1982). Through comparison with recently studied Early to Middle Jurassic radiolarians in North America and Turkey, the radiolarian assemblage reported herein is regarded to be most probably of late Early to early Middle Jurassic (Late Pliensbachian to Bajocian?) age.
