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Hystrichokolpoma eisenackii ssp. eisenackii
Hystrichokolpoma eisenackii ssp. eisenackii
Autonym, now redundant.
Holotype: Williams and Downie, 1966, pl.17, fig.2
Locus typicus: London Clay, Sheppey, Kent, England
Stratum typicum: Eocene
Original diagnosis: Williams and Downie 1966, p. 176-177
Ellipsoidal central body with wall composed of two closely appressed layers-the smooth or granular endophragm and the thinner smooth periphragm. Endophragm continuing uninterrupted beneath processes formed from periphragm. Processes of two types, large ones with quadrate bases, cylindrical or tapering with open ends, and small slender processes, with ends open or closed. Antapical process much longer than others. Tabulation typical for genus. Number of slender processes on each cingular plate limited to two. Cingulum helicoidal. Anterior sulcal process considerably larger than other sulcals.
Dimensions: Range of dimensions observed: diameter of central body: 40-57 Ám; Length of broad processes: 20-30 Ám; Antapical process up to 47 Ám; Width of broad processes: 12-27 Ám; Length of slender processes: 13-20 Ám; Width of slender processes: 0.5-4 Ám.
Original description: Williams and Downie 1966, p. 178
H.eisenacki is characterised by the broad processes which taper distally to a restricted opening with entire or serrate margin. Frequently branching off from the large processes are small erect tubules with an open serrate distal margin; commonly there are three or four on each process. The equatorial processes are simple or branched, slender with slightly expanded distal openings. The four apical plates are rarely present; the archaeopyle has a broad sulcal notch. In the precingular series of plates, plate 6"" and its attendend process are considerably smaller than the other five plates and processes, being comparable in size to the anterior sulcal plate and process. In the postcingular series, plate 1""" and its process are the smallest of the series, the other four plates and processes approaching the precingular in size. The longest process, which tapers before expanding distally, marks the position of the single antapical plate. This process is usually closed and unbranched. There are six sulcal processes, one very large anterior processes and five very slender open or bifid or acuminate processes lying between plates 1""" and 5""". The single posterior intercalary process is little different in size and structure to the slender sulcal processes and occupies a position between 1""" and 1"""". The apical processes are usually simple, occasionally branched, tapering and open distally.
Autonym, now redundant.
Holotype: Williams and Downie, 1966, pl.17, fig.2
Locus typicus: London Clay, Sheppey, Kent, England
Stratum typicum: Eocene
Original diagnosis: Williams and Downie 1966, p. 176-177
Ellipsoidal central body with wall composed of two closely appressed layers-the smooth or granular endophragm and the thinner smooth periphragm. Endophragm continuing uninterrupted beneath processes formed from periphragm. Processes of two types, large ones with quadrate bases, cylindrical or tapering with open ends, and small slender processes, with ends open or closed. Antapical process much longer than others. Tabulation typical for genus. Number of slender processes on each cingular plate limited to two. Cingulum helicoidal. Anterior sulcal process considerably larger than other sulcals.
Dimensions: Range of dimensions observed: diameter of central body: 40-57 Ám; Length of broad processes: 20-30 Ám; Antapical process up to 47 Ám; Width of broad processes: 12-27 Ám; Length of slender processes: 13-20 Ám; Width of slender processes: 0.5-4 Ám.
Original description: Williams and Downie 1966, p. 178
H.eisenacki is characterised by the broad processes which taper distally to a restricted opening with entire or serrate margin. Frequently branching off from the large processes are small erect tubules with an open serrate distal margin; commonly there are three or four on each process. The equatorial processes are simple or branched, slender with slightly expanded distal openings. The four apical plates are rarely present; the archaeopyle has a broad sulcal notch. In the precingular series of plates, plate 6"" and its attendend process are considerably smaller than the other five plates and processes, being comparable in size to the anterior sulcal plate and process. In the postcingular series, plate 1""" and its process are the smallest of the series, the other four plates and processes approaching the precingular in size. The longest process, which tapers before expanding distally, marks the position of the single antapical plate. This process is usually closed and unbranched. There are six sulcal processes, one very large anterior processes and five very slender open or bifid or acuminate processes lying between plates 1""" and 5""". The single posterior intercalary process is little different in size and structure to the slender sulcal processes and occupies a position between 1""" and 1"""". The apical processes are usually simple, occasionally branched, tapering and open distally.