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Actinomma yosii Nakaseko, 1959

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Shell rather small, entirely globular, with three concentric spheres, and 12 radial spines; these spines straight, fairly short, about 0.3, the diameter of the cortical shell in length, swordlike, with three blades; cortical shell globular, with about ten to fourteen pores scross the diameter; its pores small, regular, circular, fairly uniform in size, deeply set into the thick wall, and with the hexagonal frames; surface of the shell being generally roughened with the small sepaloid points; secondary medullary shell in the ratio of about 0.3 to 1 of the cortical shell in diameter, with thin wall, and with about seven pores across the diameter, its pores small, regular, circular, uniform in size, with fairly thin bars; primary medullary shell in the ratio of about 0.15 to 1 of the cortical shell in diameter; supporting beams rodlike, thin, 12 in number, and internal extensions of the main radial spines.
Nakaseko 1959


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