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Lejeunecysta epidoma
Lejeunecysta epidoma Matsuoka, 1987, p.59-60, pl.9, figs.5-6.
Questionable assignment: Matsuoka (1987, p.59).
Holotype: Matsuoka, 1987, pl.9, figs.5-6.
Age: Quaternary.
Original description (Matsuoka, 1987):
Lejeunecysta l epidoma sp. nov. Plate 9, figures 5-6
Deviation of name : Latin epi+domus, upper+dome, with reference to the dome shaped epicyst.
Diagnosis : Large proximate cysts lightly brownish-pigmented, consisting smooth to finely granular autophragm. Epicyst broad dome-shaped without apical boss or node. Hypocyst large, trapezoidal at optical cross section in dorso-ventral view, possessing two very small antapical horns with thickened distal tips. Paracingulum indicated by indentation of autophragm with some longitudinal striations. Parasulcus also shown by shallow indentation of autophragm. Sometimes two traces of flagellar pore present in the parasulcus. Archeopyle hexagonal intercalary, with four long and two short principal archeopyle suture (steno-delta form).
Holotype : Slide no. AK2-1 (15.2/131.7) ; PL 9, figs. 5-6, sample no. AK2, Recent sediment in Akkeshi Bay, Hokkaido, North Japan.
Dimensions : Cyst length 74.6-84.0 µm, width 74.6-80.0 µm, width of the paracingulum ca. 8 µm (Holotype 84.0^mx76.4 µm).
Number of specimens observed : 3.
Remarks : This species is very distinctive and easily distinguishable from other cysts of Protoperidinium in possessing a broadly dome-like epicyst and a large trapezoidal hypocyst.
Equivalent thecate form : Unknown, but probably Protoperidinium sp. (Conica group) , judging from its steno-delta form intercalary archeopyle, and brownish pigmentation.
Questionable assignment: Matsuoka (1987, p.59).
Holotype: Matsuoka, 1987, pl.9, figs.5-6.
Age: Quaternary.
Original description (Matsuoka, 1987):
Lejeunecysta l epidoma sp. nov. Plate 9, figures 5-6
Deviation of name : Latin epi+domus, upper+dome, with reference to the dome shaped epicyst.
Diagnosis : Large proximate cysts lightly brownish-pigmented, consisting smooth to finely granular autophragm. Epicyst broad dome-shaped without apical boss or node. Hypocyst large, trapezoidal at optical cross section in dorso-ventral view, possessing two very small antapical horns with thickened distal tips. Paracingulum indicated by indentation of autophragm with some longitudinal striations. Parasulcus also shown by shallow indentation of autophragm. Sometimes two traces of flagellar pore present in the parasulcus. Archeopyle hexagonal intercalary, with four long and two short principal archeopyle suture (steno-delta form).
Holotype : Slide no. AK2-1 (15.2/131.7) ; PL 9, figs. 5-6, sample no. AK2, Recent sediment in Akkeshi Bay, Hokkaido, North Japan.
Dimensions : Cyst length 74.6-84.0 µm, width 74.6-80.0 µm, width of the paracingulum ca. 8 µm (Holotype 84.0^mx76.4 µm).
Number of specimens observed : 3.
Remarks : This species is very distinctive and easily distinguishable from other cysts of Protoperidinium in possessing a broadly dome-like epicyst and a large trapezoidal hypocyst.
Equivalent thecate form : Unknown, but probably Protoperidinium sp. (Conica group) , judging from its steno-delta form intercalary archeopyle, and brownish pigmentation.