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Kallosphaeridium spongiosum
Kallosphaeridium? spongiosum Batten and Lister, 1988
Batten and Lister, 1990, questionably included this species in Kallosphaeridium.
Holotype: Batten and Lister, 1988, figs.4e-g
Locus typicus: Warlingham Borehole, Surrey, depth 442 m, lower division of the Weald Clay Group
Stratum typicum: Late Hauterivian
Original diagnosis: Batten and Lister, 1988, p.344-345
Small, subspherical, proximate, thin-walled (c. 1 Ám) cyst; maximum diameter 30(34)37 x 30(36)40 Ám (10 specimens). Wall an autophragm, surface densely covered with small granules and short (c.1 Ám) pila, sometimes forming thickened vermiculate structures. Typically, sculptural elements coalesce to form a spongy, delicate ectophragm but this is not always obviously displayed. Paratabulation usually weakly expressed by a more pronounced granulation along parasutural boundaries than elsewhere. Archeopyle apical/?intercalary, operculum angular in outline and ventrally adnate. Archeopyle margin formed by camerate precingular paraplates frequently separated by deep accessory sutures.
Batten and Lister, 1990, questionably included this species in Kallosphaeridium.
Holotype: Batten and Lister, 1988, figs.4e-g
Locus typicus: Warlingham Borehole, Surrey, depth 442 m, lower division of the Weald Clay Group
Stratum typicum: Late Hauterivian
Original diagnosis: Batten and Lister, 1988, p.344-345
Small, subspherical, proximate, thin-walled (c. 1 Ám) cyst; maximum diameter 30(34)37 x 30(36)40 Ám (10 specimens). Wall an autophragm, surface densely covered with small granules and short (c.1 Ám) pila, sometimes forming thickened vermiculate structures. Typically, sculptural elements coalesce to form a spongy, delicate ectophragm but this is not always obviously displayed. Paratabulation usually weakly expressed by a more pronounced granulation along parasutural boundaries than elsewhere. Archeopyle apical/?intercalary, operculum angular in outline and ventrally adnate. Archeopyle margin formed by camerate precingular paraplates frequently separated by deep accessory sutures.