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Leptodinium norrisii
Leptodinium norrisii Pocock, 1972
Originally Leptodinium, subsequently Dichadogonyaulax thirdly Ctenidodinium, fourthly Korystocysta.
Tax. jr. synonyrn of Gonyaulax (as Korystocysta) pachyderma Deflandre, 1938, according to Benson, 1985.
Tax. sr. synonym of Dichadogonyaulax (now Korystocysta) kettonensis Sarjeant, 1967, according to Conway, 1990, who also included in synonymy Gonyaulax pachyderma. If the two species are tax. synonyms, then Gonyaulax pachyderma is the sr. synonym of Dichadogonyaulax 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
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.
Tax. jr. synonyrn of Gonyaulax (as Korystocysta) pachyderma Deflandre, 1938, according to Benson, 1985.
Tax. sr. synonym of Dichadogonyaulax (now Korystocysta) kettonensis Sarjeant, 1967, according to Conway, 1990, who also included in synonymy Gonyaulax pachyderma. If the two species are tax. synonyms, then Gonyaulax pachyderma is the sr. synonym of Dichadogonyaulax 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
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.