Taxonomy of Late Silurian to Middle Devonian radiolarians from the KuzuryuLake district of the Hida Gaien Belt, Fukui Prefecture, central Japan

Moderately well-preserved late Late Silurian (Ludlowian to Pridolian) to ea rly Middle Devonian (Eifelian) radiolarians were recovered from elastic roc k sequences in the Kuzuryu Lake district of the Hida Gaien Belt, Fukui Pref ecture, central Japan. These radiolarians are identical to the faunas of th e following four assemblages: Zadrappolus yoshikiensis (Late Silurian; Ludl owian to Pridolian), Pseudospongoprunum sagittatum (latest Silurian; Pridol ian), Zadrappolus sp. aff. Z, spinosus (latest Silurian to earliest Devonia n; Pridolian to Lochkovian) and Pactarentinia holdsworthi (Early to Middle Devonian; Emsian to Eifelian) Assemblages. These radiolarian faunas from th e Hida Gaien Belt are correlative with those of the Kurosegawa Belt (Outer Belt of southwest Japan). Silurian radiolarian faunas from the Hida Gaien a nd Kurosegawa Belts are similar to those from West Junggar in westernmost C hina. The Early and Middle Devonian radiolarian faunas in Japan are differe nt from those in eastern Australia in that the Japanese faunas characterist ically contain "shelled Palaeoscenidiidae". Thus, based on radiolarian faun al similarity, Silurian and Devonian radiolarian-bearing rock sequences in Japan are inferred to have accumulated in the sea nearer to the Sino-Korean Continent than to eastern Australia in the low latitude of Gondwana. Radiolarians of 26 species belonging to 13 genera were systematically inves tigated. Ten new species are described: Palaeoscenidium simplum, Palaeoscen idium hakogasensis, Palaeoscenidium fragilis, Deflantrica furutanii, Pactar entinia intermedia, Pactarentinia igoi, Tlecerina isensis, Ceratoikisum izu miensis, Palaeopyramidium ramosum and Palaeoumbraculum hidense.