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Korystocysta norrisii
Korystocysta norrisii (Pocock, 1972) Woolam, 1983
Originally Leptodinium, subsequently Dichadogonyaulax, thirdly Ctenidodinium, fourthly Korystocysta.
Taxonomic senior synonym: Gonyaulax (now Korystocysta) pachyderma, according to Benson (1985, p.154).
Taxonomic junior synonym: Dichadogonyaulax (subsequently Korystocysta) kettonensis, by implication in Conway (1990, p.35), who considered Dichadogonyaulax (as Korystocysta) kettonensis to be the senior name - however, Lentin and Williams (1993, p.374) retained Dichadogonyaulax (as Korystocysta) kettonensis.
Holotype: Pocock, 1972, pl.24, fig.9; Jansonius, 1986, pl.2, figs.6-8, text-fig.5
Locus typicus: Imperial Tidewater Wapalla, W Canada
Stratum typicum: Callovian
Original description: Pocock, 1972, p.92: Leptodinium norrisii
Theca more or less isodiametric; both hypotheca and epitheca more or less hemispherical; apical horn reduced or absent; represented by the small plate 4"; slightly helicoidal equatorial girdle well developed; forms a band of weakness along which the theca splits into two hemispheres (epithecal archeopyle with a simple operculum); longitudinal furrow more or less same width on epitheca and hypotheca; tabulation 4", 1a, 6", 5""", 1""""; sutures well delineated; cingular plates shield-shaped, each with a very narrow ridge developed on the face of the plate parallel to the suture (see diagram); sutures mark lines of weakness and isolated plates readily split off from the theca resulting in the presence of loose plates in most preparations; thecal wall about 2.0 Ám thick; infrapunctate; internally smooth; external surface punctate; lines of the sutures, particularly around the equatorial girdle and the 1"""" plate, ornamented with crowded, very fine, pinnate spines about 1.0-5.0 Ám Iong and 0.2 Ám--1.0 Ám wide, spaced about 1.0 Ám apart; colour pale yellow; length of theca 60.0 (89.0) 126.0 Ám; equatorial diameter 66.0 (87.0) 110.0 Ám.
Originally Leptodinium, subsequently Dichadogonyaulax, thirdly Ctenidodinium, fourthly Korystocysta.
Taxonomic senior synonym: Gonyaulax (now Korystocysta) pachyderma, according to Benson (1985, p.154).
Taxonomic junior synonym: Dichadogonyaulax (subsequently Korystocysta) kettonensis, by implication in Conway (1990, p.35), who considered Dichadogonyaulax (as Korystocysta) kettonensis to be the senior name - however, Lentin and Williams (1993, p.374) retained Dichadogonyaulax (as Korystocysta) kettonensis.
Holotype: Pocock, 1972, pl.24, fig.9; Jansonius, 1986, pl.2, figs.6-8, text-fig.5
Locus typicus: Imperial Tidewater Wapalla, W Canada
Stratum typicum: Callovian
Original description: Pocock, 1972, p.92: Leptodinium norrisii
Theca more or less isodiametric; both hypotheca and epitheca more or less hemispherical; apical horn reduced or absent; represented by the small plate 4"; slightly helicoidal equatorial girdle well developed; forms a band of weakness along which the theca splits into two hemispheres (epithecal archeopyle with a simple operculum); longitudinal furrow more or less same width on epitheca and hypotheca; tabulation 4", 1a, 6", 5""", 1""""; sutures well delineated; cingular plates shield-shaped, each with a very narrow ridge developed on the face of the plate parallel to the suture (see diagram); sutures mark lines of weakness and isolated plates readily split off from the theca resulting in the presence of loose plates in most preparations; thecal wall about 2.0 Ám thick; infrapunctate; internally smooth; external surface punctate; lines of the sutures, particularly around the equatorial girdle and the 1"""" plate, ornamented with crowded, very fine, pinnate spines about 1.0-5.0 Ám Iong and 0.2 Ám--1.0 Ám wide, spaced about 1.0 Ám apart; colour pale yellow; length of theca 60.0 (89.0) 126.0 Ám; equatorial diameter 66.0 (87.0) 110.0 Ám.