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Alisocysta circumtabulata
Alisocysta circumtabulata, (Drugg, 1967), Stover and Evitt, 1978
Originally Eisenackia, subsequently Hystrichokolpoma, thirdly (and now) Alisocysta, fourthly Agerasphaera (generic name illegitimate). Fensome et al. (in press) retained this species in Alisocysta.
Tax. jr. syn.: Hystrichokolpoma mentitum, according to Schumacker-Lambry (1978, p.42) — however, Lentin and Williams (1981, p.135) retained Hystrichokolpoma mentitum.
Holotype: Drugg, 1967, pl.1, fig.12; Damassa, 1979b, pl.3, figs.14–16; Fensome et al., 1993a, fig.1 — p.1061.
Paratype: Drugg, 1967
Locus typicus: Escarpado Canyon, California, U.S.A.
Stratum typicum: Danian
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Original description as Eisenackia circumtabulata: [Drugg, W. 1967, p. 15]:
Diagnosis:
Test ellipsoidal in outline, somewhat compressed. Wall thick, very finely punctate on some specimens. The plates are delineated by low membranous walls.
The tabulation is identical to that of Eisenackia crassitabulata Deflandre and Cookson 1955. The test opens by means of an apical operculum.
Dimensions/Size range:
36 to 47 µm wide, 37 to 47 µm high (six specimens).
Affinities:
This species differs from Eisenackia crassitabulata in that the plates are marked by raised walls, the interiors of which are not filled with a thick-walled mesh.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Alisocysta circumtabulata (Drugg, 1967) Stover and Evitt, 1978, has a thick wall, very finely punctate on some specimens. The plates are delineated by low membranous walls.
Size: length 37-47 µm, breadth 36-47 µm.
Originally Eisenackia, subsequently Hystrichokolpoma, thirdly (and now) Alisocysta, fourthly Agerasphaera (generic name illegitimate). Fensome et al. (in press) retained this species in Alisocysta.
Tax. jr. syn.: Hystrichokolpoma mentitum, according to Schumacker-Lambry (1978, p.42) — however, Lentin and Williams (1981, p.135) retained Hystrichokolpoma mentitum.
Holotype: Drugg, 1967, pl.1, fig.12; Damassa, 1979b, pl.3, figs.14–16; Fensome et al., 1993a, fig.1 — p.1061.
Paratype: Drugg, 1967
Locus typicus: Escarpado Canyon, California, U.S.A.
Stratum typicum: Danian
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Original description as Eisenackia circumtabulata: [Drugg, W. 1967, p. 15]:
Diagnosis:
Test ellipsoidal in outline, somewhat compressed. Wall thick, very finely punctate on some specimens. The plates are delineated by low membranous walls.
The tabulation is identical to that of Eisenackia crassitabulata Deflandre and Cookson 1955. The test opens by means of an apical operculum.
Dimensions/Size range:
36 to 47 µm wide, 37 to 47 µm high (six specimens).
Affinities:
This species differs from Eisenackia crassitabulata in that the plates are marked by raised walls, the interiors of which are not filled with a thick-walled mesh.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Alisocysta circumtabulata (Drugg, 1967) Stover and Evitt, 1978, has a thick wall, very finely punctate on some specimens. The plates are delineated by low membranous walls.
Size: length 37-47 µm, breadth 36-47 µm.