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Hurunuia
From Williams et al., 2017:
[Hurunuia, Wilson, 1984a, p. 215-216
Type species: Hurunuia maxwellii, Wilson, 1984a (figs.2A–B, 3–5)]
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Original description: [Wilson, 1984]:
Description:
Moderately large elongate bicavate cysts with horns reduced or lacking. Periphragm and endophragm in close contact except near the apex and in the lower hypocyst. Apical pericoel short, tapered; antapical pericoel broad, rounded.
Paratabulation indicated by low parasutural features, apparently gonyaulacacean; probable formula ?pr, 4`, 6", Xc, 5-6```, 0-1 p, 1````, Xs. Paracingulum and parasulcus delimited by low ridges.
Archeopyle apical, type tA; operculum free.
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Modified description:
Stover and Williams, 1987, p. 125:
Synopsis:
Cysts proximate, elongate ellipsoidal, bicavate; gonyaulacacean paratabulation indicated by parasutural ridges, formula: ?pr, 4`, 6", 0-6c, 5-6```, 0-1 p, 1````; archeopyle apical, type [4A].
Description:
Shape: Pericyst elongate ellipsoidal with the apical end more narrowly rounded than the antapical end; endocyst ellipsoidal.
Wall relationships: Cysts bicavate; hypopericoel larger than epipericoel.
Wall features: Parasutural ridges usually developed better dorsally than ventrally; endophragm smooth, periphragm finely reticulate to perforate.
Archeopyle: Apical, type [4A], principal suture angular; operculum free.
Paratabulation: Indicated by parasutural features; gonyaulacacean, formula: ?pr, 4`, 6", 0-6c, 5-6```, 0-1 p, 1````.
Paracingulum: Indicated by parasutural ridges, commonly subdivided.
Parasulcus: Large, usually with one, poorly defined paraplate.
Size: Intermediate to large, length about 80 to105 µm (without opercula), 115 µm with opercula.
Affinities:
Hurunuia differs from Clathroctenocystis Wiggins 1972, in being cavate and from Belodinium Cookson and Eisenack 1960, in being bicavate rather than holocavate and in lacking a prominent apical horn. As stated by Wilson (1984, p. 216) Hurunuia differs from Ascodinium Cookson and Eisenack 1960 emended Helenes 1983 in having a definite paratabulation and an apical, not a combined apical and intercalary archeopyle. Psaligonyaulax Sarjeant in Davey et al. 1966 emended Sarjeant 1982, which is bicavate, has a precingular archeopyle.
[Hurunuia, Wilson, 1984a, p. 215-216
Type species: Hurunuia maxwellii, Wilson, 1984a (figs.2A–B, 3–5)]
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Original description: [Wilson, 1984]:
Description:
Moderately large elongate bicavate cysts with horns reduced or lacking. Periphragm and endophragm in close contact except near the apex and in the lower hypocyst. Apical pericoel short, tapered; antapical pericoel broad, rounded.
Paratabulation indicated by low parasutural features, apparently gonyaulacacean; probable formula ?pr, 4`, 6", Xc, 5-6```, 0-1 p, 1````, Xs. Paracingulum and parasulcus delimited by low ridges.
Archeopyle apical, type tA; operculum free.
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Modified description:
Stover and Williams, 1987, p. 125:
Synopsis:
Cysts proximate, elongate ellipsoidal, bicavate; gonyaulacacean paratabulation indicated by parasutural ridges, formula: ?pr, 4`, 6", 0-6c, 5-6```, 0-1 p, 1````; archeopyle apical, type [4A].
Description:
Shape: Pericyst elongate ellipsoidal with the apical end more narrowly rounded than the antapical end; endocyst ellipsoidal.
Wall relationships: Cysts bicavate; hypopericoel larger than epipericoel.
Wall features: Parasutural ridges usually developed better dorsally than ventrally; endophragm smooth, periphragm finely reticulate to perforate.
Archeopyle: Apical, type [4A], principal suture angular; operculum free.
Paratabulation: Indicated by parasutural features; gonyaulacacean, formula: ?pr, 4`, 6", 0-6c, 5-6```, 0-1 p, 1````.
Paracingulum: Indicated by parasutural ridges, commonly subdivided.
Parasulcus: Large, usually with one, poorly defined paraplate.
Size: Intermediate to large, length about 80 to105 µm (without opercula), 115 µm with opercula.
Affinities:
Hurunuia differs from Clathroctenocystis Wiggins 1972, in being cavate and from Belodinium Cookson and Eisenack 1960, in being bicavate rather than holocavate and in lacking a prominent apical horn. As stated by Wilson (1984, p. 216) Hurunuia differs from Ascodinium Cookson and Eisenack 1960 emended Helenes 1983 in having a definite paratabulation and an apical, not a combined apical and intercalary archeopyle. Psaligonyaulax Sarjeant in Davey et al. 1966 emended Sarjeant 1982, which is bicavate, has a precingular archeopyle.