A new fossil marine diatom resting spore morpho-genus Gemellodiscus Suto gen. nov. is described using samples from DSDP Site 338 in the Norwegian Sea, Sites 436 and 438 in the northwest Pacific and the onland Newport Beach Section, California. Gemellodiscus is characterized by possessing a valve with setae of several types: bifurcated seta, fused seta and crossed seta. Eleven taxa are described and their stratigraphic ranges are presented: G. incurvus (Bailey) Suto comb. nov., G. pliocenus (Brun) Suto comb. nov., G. cingulus Suto var. cingulus sp. nov., G. cingulus var. longus Suto var. nov., G. bifurcus Suto sp. nov., G. hirtus Suto sp. nov., G. caveatus Suto sp. nov., G. micronodosus Suto sp. nov., G. dicollinus Suto sp. nov., G. geminus Suto sp. nov. and G. dimontanus Suto sp. nov.

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Fossil marine diatom resting spore species in the morpho-genus Xanthiopyxis Ehrenberg are described using samples from DSDP Site 338 in the Norwegian Sea, Sites 436 and 438 in the northwest Paciffic and from the onland section at Newport Beach, California. Xanthiopyxis is characterized by numerous knobs, spines and bristles covering the entire valve face. In this paper eleven species, of which seven are new species, are described and their stratigraphic ranges are presented: X. polaris Gran, X. norwegica Suto, sp. nov., X. brevispinosa Suto, sp. nov., X. teneropunctata Suto, sp. nov., X. lanceolatus Suto, sp. nov. X. circulatus Suto, sp. nov., X. reticulata Suto, sp. nov., X. obesa Suto, sp. nov., X. hirsuta Hanna and Grant, X. oblonga Ehrenberg and X. globosa Ehrenberg. In addition, resting spores which lack sufficient characteristics to identify easily are assigned to three informal species: Xanthiopyxis type A (knobbly type), X. type B (short spiny type) and X. type C (long spiny type).

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The pattern of shell breakage in the Recent trochid gastropods Umbonium (Suchium) mon iliferum (Lamarck) and U. (S.) giganteum (Lesson) was observed under durophagous predation by crabs and in tumbling experiments, and the results of these experiments were applied to recent population samples from the natural environment. The experiments were carried out in order to learn if the pattern of shell breakage by durophagy (shell crushing) is different from that induced by water currents and waves. After predation by the predatory crabs Calappa tophos (Herbst) and Portunus trituberculatus (Miers), shell apertures of U. (S.) monitiferum and U. (S.) giganteum were broken in a characteristic fashion. In contrast, shells tumbled with sand and artificial seawater rarely lost the apertural margins, although other parts of the shells were relatively severely abraded. These results suggest that a shell from the natural environment with a similarly broken apertural margin was probably attacked by a durophagous crab, and that water currents and waves are not agents that cause breakage of shell apertures. The results were then applied to samples of Recent U. (S.) moniliferum from Lake Hamana-ko and fossil U. (S.) costatum (Kiener) from the Pleistocene Jizodo Formation in Japan. Shells with broken apertural margins amounted to 60% of all dead empty shells in the sample of Recent U. (S.) moniliferum, and over 90% in the sample of Pleistocene U. (S.) costatum, suggesting that these shells were extensively preyed upon by durophagous crabs. Shell repair frequencies of Recent U. (S.) moniliferum, calculated as a percentage of individuals with one or more repair scars, were 24-55%. The high repair frequencies indicate that considerable numbers of U. (S.) moniliferum can escape from attacks by crabs. All the results suggest that shell breakage along the apertural margins of gastropods is a good indicator of durophagy and that broken apertures, as well as shell repairs, are a useful tool for the investigation of predatory-prey interaction.

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Late Jurassic and Early Cretaceous well preserved radiolarians are obtained from the Taukha Terrane in the southern Sikhote-Alin, Russia. The Taukha Terrane consists of three tectono-stratigraphic units, the Erdagou, Gorbousha and Skalistorechenka units. Three new species (Stichocapsa (?) pseudoconvexa, Sethocapsa taukhaensis and Cingutoturris primorika) are described from Late Jurassic chertterrigenous sequences of the Gorbousha Unit cropping out in the Roudnaya River and Koreyskaya River areas, and their stratigraphic ranges are made precise.

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