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Homotryblium umbellatum
Homotryblium umbellatum Islam, 1983
Holotype: Islam, 1983, pl.3, fig.7
Paratype: Islam, 1983
Locus typicus: Hampshire Basin, S England
Stratum typicum: Early Eocene
Original diagnosis: Islam, 1983, p. 340
Cyst ellipsoidal, skolochorate and biphragmal; periphragm chagrinate; intratabular tubular processes with wider circular or oval bases tapering to narrower necks before distally ramifying into circular umbrella-like membranous expansions bearing six equally spaced spinules at extremities, sometimes recurved; frequently "umbrella" is deformed; processes open at both ends; paratabulation observed from one process per paraplate defining 6c, 6""", 1p, ps, 1"""" archeopyle epicystal, operculum not seen but isolated paraplates found could be opercular pieces.
Dimensions: Cyst body 30 x 42 µm (without operculum), length of processes 15-18 µm. Range: cyst breadth 42(40)36 µm, dorsoventral thickness 34(32)31 µm, length of processes 9-18 µm.
Affinities:
Islam, 1983, p. 340: This species differs from others of the genus, particularly from Homotryblium pallidum Davey and Williams 1966 and H. tenuispinosum, to which it bears some resemblance in possessing the umbrellalike distal ramifications of the processes.
Holotype: Islam, 1983, pl.3, fig.7
Paratype: Islam, 1983
Locus typicus: Hampshire Basin, S England
Stratum typicum: Early Eocene
Original diagnosis: Islam, 1983, p. 340
Cyst ellipsoidal, skolochorate and biphragmal; periphragm chagrinate; intratabular tubular processes with wider circular or oval bases tapering to narrower necks before distally ramifying into circular umbrella-like membranous expansions bearing six equally spaced spinules at extremities, sometimes recurved; frequently "umbrella" is deformed; processes open at both ends; paratabulation observed from one process per paraplate defining 6c, 6""", 1p, ps, 1"""" archeopyle epicystal, operculum not seen but isolated paraplates found could be opercular pieces.
Dimensions: Cyst body 30 x 42 µm (without operculum), length of processes 15-18 µm. Range: cyst breadth 42(40)36 µm, dorsoventral thickness 34(32)31 µm, length of processes 9-18 µm.
Affinities:
Islam, 1983, p. 340: This species differs from others of the genus, particularly from Homotryblium pallidum Davey and Williams 1966 and H. tenuispinosum, to which it bears some resemblance in possessing the umbrellalike distal ramifications of the processes.