Lower and Middle Jurassic Radiolaria (Multicyrtid Nassellariina) from California, East-Central Oregon and the Queen Charlotte Islands, B.C.

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Abstract
Multicyrtid Nassellariina from Lower and Middle Jurassic strata in California, east-central Oregon and the Queen Charlotte Islands, British Columbia, are discussed. New families [CANUTIDAE, BAGOTIDAE and HSUIDAE], new genera [BAGOTUM (type species: B. maudense sp. nov.); BROCTUS (type species: B. selwynensis sp. nov.); DROLTUS (type species: D. lyellensis sp. nov.): NORITUS (type species: N. lillihornensis sp. nov.); RELANUS (type species R. reefensis sp. nov.); WRANGELLIUM (type species: W. thurstonense sp. nov.); CANUTUS (type species: C. tipperi sp. nov.); LUPHERIUM (type species: L. snowhoense sp. nov.); and RISTOLA (type species: Parvicingula (?) procera Pessagno, 1977a.)] and 47 new species are described. Preliminary range zone data are presented for all species. Test structure rather than test shape is emphasized in the definition of families and genera; this should lead to a more phylogenetic classification of the taxa. Multicyrtid Nassellariina and probably all Nassellariina display a lamellar mode of test construction analogous to that displayed by the hyaline Foraminiferida. The distinction is made between layered test walls, a common feature of many Mesozoic genera (e.g., Xitus Pessagno, Mirifusus Pessagno, Canoptum Pessagno) and lamellar structure. Layered tests may consist of bundles of lamellae. Indirect evidence supporting a lamellar mode of test construction includes test thickening and an increase in the strength of development of ornamental features in an apical direction. Direct evidence supporting such a model awaits phase optics studies of tests unaffected by diagenetic change.

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