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Impletosphaeridium petalum
Impletosphaeridium petalum Islam, 1983
Holotype: Islam, 1983, pl.4, fig.1
Paratypes: Islam, 1983
Locus typicus: Sheppey, England
Stratum typicum: Middle Eocene
Original diagnosis: Islam, 1983, p. 88
Cyst subspherical, proximochorate and biphragmal; endophragm chagrinate or mildly reticulate; periphragm chagrinate; possesses many nontabular variably broad platy and solid processes with a few interspersed thin solid slender ones, all process types proximally little wide, sometimes join with neighbouring ones to increase in breadth, distally branched, platy ones branch more variably; grouping of some processes sometimes imparts an image of partial paratabulation; roughly circular pylome often seen. Dimensions: Holotype: cyst body 31 x 31 Ám, length of processes 6-8 µm. Range: cyst length 26(31)32 µm, breadth 26(29)31 µm, length of
processes 5-8 µm.
Affinities:
Islam, 1983, p. 88: The species differs from other species of the genus in possessing platy solid processes bearing variable distal branchlets. It resembles I. kroemmelbeini Morgenroth 1966 but differs in possessing shorter processes which are up to a quarter of mean cyst diameter, and distally branched as against distally bifurcate, multifurcate and digitate processes with typically aculeate distal terminations in I. kroemmelbeini.
Holotype: Islam, 1983, pl.4, fig.1
Paratypes: Islam, 1983
Locus typicus: Sheppey, England
Stratum typicum: Middle Eocene
Original diagnosis: Islam, 1983, p. 88
Cyst subspherical, proximochorate and biphragmal; endophragm chagrinate or mildly reticulate; periphragm chagrinate; possesses many nontabular variably broad platy and solid processes with a few interspersed thin solid slender ones, all process types proximally little wide, sometimes join with neighbouring ones to increase in breadth, distally branched, platy ones branch more variably; grouping of some processes sometimes imparts an image of partial paratabulation; roughly circular pylome often seen. Dimensions: Holotype: cyst body 31 x 31 Ám, length of processes 6-8 µm. Range: cyst length 26(31)32 µm, breadth 26(29)31 µm, length of
processes 5-8 µm.
Affinities:
Islam, 1983, p. 88: The species differs from other species of the genus in possessing platy solid processes bearing variable distal branchlets. It resembles I. kroemmelbeini Morgenroth 1966 but differs in possessing shorter processes which are up to a quarter of mean cyst diameter, and distally branched as against distally bifurcate, multifurcate and digitate processes with typically aculeate distal terminations in I. kroemmelbeini.