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Herendeenia
From Fensome et al., 2019:
Herendeenia, Wiggins, 1969, p.145–146.
Taxonomic senior synonym: Omatia, according to Stover and Evitt (1978, p.280) -- however, Stover and Helby (1987b, p.153–154) retained Herendeenia. Stover and Helby (1987b, p.153–154) gave a "redescription" of this genus.
Type: Cookson and Eisenack, 1958, pl.8, fig.6, as Omatia pisciformis.
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Original description: [Wiggins, 1969]:
Diagnosis:
The cyst is fusiform in outline, with the tabulation 3`, 6``, 7c, 6```, 1p, 1````. The archaeopyle is precingular and is formed by the 3`` plate. The apical, precingular, postcingular, and posterior intercalary plates are either completely or partially delineated by finlike membranes.
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Modified description:
Stover and Helby, 1987, p. 153-154:
Synopsis:
Cysts proximate, elongate ellipsoidal; wall layers appressed over most of cyst, periphragm forming apical projection and parasutural ridges or folds in the apical and antapical areas, which diminish in height and clarity equatorially; paratabulation indicated partly by parasutural features and may be indicated additionally by parasutures and/or faint linear markings; formula 3-4`, 5-6` `, X-6c, 4- 5```, O-lp, 1````; archeopyle precingular, 3`` only.
Description:
Shape: Cysts elongate ellipsoidal with an apical protrusion and generally a truncated antapical margin.
Wall relationships: Wall appressed except apically and antapically where ridge or folds are formed by the periphragm.
Wall features: Parasutural features consist of ridges or folds in the apical and antapical areas; elsewhere faint linear markings and parasutures may be formed. Periphragm uniformly ornamented with features of low relief.
Archeopyle: Precingular, type P, 3`` only; operculum free.
Paratabulation: Gonyaulacacean, indicated in polar areas by parasutural ridges or folds; indications in other areas may be absent, or expressed by parasutures, or faint linear markings, or both. Formula 3-4`, 5-6``, X-6c, 4-5```, O-lp, 1````.
Paracingulum: Expressed by 6 paraplates (some 4-sided, some 6-sided) delimited completely or partly by sutures and faint linear markings, or paracingulum not indicated.
Parasulcus: Not clearly indicated; position inferred from outlines of adjacent paraplates.
Size: Intermediate to large, generally greater than 100 µm in length.
Affinities:
Herendeenia differs from Omatia in having the wall layers appressed over most of the cyst, in possessing a precingular archeopyle and in lacking processes. The wall layers on Omatia are separated, the genus lacks an archeopyle and it has processes. Other, perhaps less important differences are that in Herendeenia the outer wall is ornamented and forms the apical projection, whereas in Omatia it is the inner wall that is ornamented and which forms the apical projection.
Herendeenia, Wiggins, 1969, p.145–146.
Taxonomic senior synonym: Omatia, according to Stover and Evitt (1978, p.280) -- however, Stover and Helby (1987b, p.153–154) retained Herendeenia. Stover and Helby (1987b, p.153–154) gave a "redescription" of this genus.
Type: Cookson and Eisenack, 1958, pl.8, fig.6, as Omatia pisciformis.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Wiggins, 1969]:
Diagnosis:
The cyst is fusiform in outline, with the tabulation 3`, 6``, 7c, 6```, 1p, 1````. The archaeopyle is precingular and is formed by the 3`` plate. The apical, precingular, postcingular, and posterior intercalary plates are either completely or partially delineated by finlike membranes.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Helby, 1987, p. 153-154:
Synopsis:
Cysts proximate, elongate ellipsoidal; wall layers appressed over most of cyst, periphragm forming apical projection and parasutural ridges or folds in the apical and antapical areas, which diminish in height and clarity equatorially; paratabulation indicated partly by parasutural features and may be indicated additionally by parasutures and/or faint linear markings; formula 3-4`, 5-6` `, X-6c, 4- 5```, O-lp, 1````; archeopyle precingular, 3`` only.
Description:
Shape: Cysts elongate ellipsoidal with an apical protrusion and generally a truncated antapical margin.
Wall relationships: Wall appressed except apically and antapically where ridge or folds are formed by the periphragm.
Wall features: Parasutural features consist of ridges or folds in the apical and antapical areas; elsewhere faint linear markings and parasutures may be formed. Periphragm uniformly ornamented with features of low relief.
Archeopyle: Precingular, type P, 3`` only; operculum free.
Paratabulation: Gonyaulacacean, indicated in polar areas by parasutural ridges or folds; indications in other areas may be absent, or expressed by parasutures, or faint linear markings, or both. Formula 3-4`, 5-6``, X-6c, 4-5```, O-lp, 1````.
Paracingulum: Expressed by 6 paraplates (some 4-sided, some 6-sided) delimited completely or partly by sutures and faint linear markings, or paracingulum not indicated.
Parasulcus: Not clearly indicated; position inferred from outlines of adjacent paraplates.
Size: Intermediate to large, generally greater than 100 µm in length.
Affinities:
Herendeenia differs from Omatia in having the wall layers appressed over most of the cyst, in possessing a precingular archeopyle and in lacking processes. The wall layers on Omatia are separated, the genus lacks an archeopyle and it has processes. Other, perhaps less important differences are that in Herendeenia the outer wall is ornamented and forms the apical projection, whereas in Omatia it is the inner wall that is ornamented and which forms the apical projection.