Subsequent to the finding of Upper Cretaceous (Maastrichtian?) submarine sediments from FL-437, another unusual core, FL-422, was recognized from the Fletcher's Ice Island T-3 in the Alpha Ridge region of the Arctic Ocean. In spite of a superficial lithological resemblance to the previous FL-437 cored sediments, the silicoflagellate and ebridian assemblage identified from the FL-422 marine deposits is best considered as Early Paleogene age. Its microfloral composition is distinctly different from all the previously published records of this group of siliceous microfossils of other parts of the world. The following new taxa are proposed : Dictyocha arctios, D. curta, and Ammodochium fletcheri. This report of Early Paleogene silicoflagellates and ebridians reconfirms the existence of pre-Miocene deep-sea sediments in the Alpha Ridge area of the Arctic Ocean, thus providing paleooceanographic evidence about geophysical and tectonic paradigm of the Arctic Ocean floor.

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This is part 2 of serial papers of the Middle Devonian (probably Eifelian) trilobite fauna from the Nakazato Formation in Northeast Honshu, Japan. A calymenid genus Nipponocalymene, gen. nov. and its type-species Nipponocalymene hamadai, gen. et sp. nov. are proposed in this part.

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The intraspecific variation within three Glossaulax species, G. hyugensis (Shuto), G. nodai, n. sp. and G. hagenoshitensis (Shuto), which had flourished in the late Cenozoic waters of Japan, was studied on the basis of more than 600 individuals collected from 24 localities. The three species overlap stratigraphically and geographically, and are distinguished from other Glossaulax species by having a nearly flat umbilical wall and a spiral angulation dividing the base and the umbilical wall. "Dimorphic" variation is recognized in the callus morphology of the adults of G. hyugensis and G. hagenoshitensis. One adult variant of G. hyugensis is similar to that of G. hagenoshitensis, and the other adult variant of the former species is similar to that of the latter, whereas the frequency of the similar adult variants of the two species is extremely different. G. nodai, however, is uniform in callus morphology throughout growth. In the callus morphology, the juvenile of G. hyugensis and that of G. hagenoshitensis are similar to G. nodai, and to one form of the adult "dimorphic" variation of G. hyugensis, respectively. Furthermore, G. hagenoshitensis is divisible into two allopatric forms in the sculpture of subsutural area and of umbilical wall margin. The mode of the ontogenetic variations of the three species is explained by a heterochronic model in which an imaginary ancestral species is presumed. G. hagenoshitensis has been taxonomically confused with Polinices sagamiensis Pilsbry and Glossaulax reiniana (Dunker), but is clearly distinguished from these two species on the basis of umbilical morphology.

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The present report describes the ontogenetic developments of Fieldaspis quadriangularis, n. sp. and Albertella limbata Rasetti from the Middle Cambrian, Alberta, Canada. The morphogenic characteristics of these two species during their different ontogenetic stages are similar to those of Bathyuriscus fimbriatus Robison and Ptarmigania aurita Resser from the North American continent. The similar ontogenetic characteristics make them a natural taxonomic group and possibly descendants from a common ancestor.

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