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Occisucysta hollisteri
Occisucysta hollisteri (Habib, 1972) Below, 1981
Now Diacanthum. Originally (and now)Diacanthum, subsequently Occisucysta.
Lentin and Williams, 1981, retained the species in Diacanthum Habib, 1972.
Holotype: Habib, 1972, pl.9, fig.1
Locus typicus: DSDP Leg 11, Atlantic Ocean
Stratum typicum: probably Valanginian
Original description: Drugg, 1972, p. 376-377: Diacanthum hollisteri
Proximate cysts compressed to a subcircular outline. Apical polar areas always wellrounded, and without horns. Periphragm and endophragm closely appressed. Cingulum is narrow, and only weakly helicoid, it divides the epitract and hypotract into more-or-less equal halves. Sulcus extends deeply into hypotract. Tabulation is that for the genus. Precingular archeopyle apparently formed by plates 3" and 4". Plate boundaries formed by raised crests which for the most part are perforate; the perforate crests do not appear to be entirely restricted to plate margins, as they extend over the periphragm, to varying degrees, as alveolae. Periphragm covered with dense grana, and by isolated broadly tapering sharp spines. Size of twenty measured specimens from 75 to 104 µm, maximum length.
Now Diacanthum. Originally (and now)Diacanthum, subsequently Occisucysta.
Lentin and Williams, 1981, retained the species in Diacanthum Habib, 1972.
Holotype: Habib, 1972, pl.9, fig.1
Locus typicus: DSDP Leg 11, Atlantic Ocean
Stratum typicum: probably Valanginian
Original description: Drugg, 1972, p. 376-377: Diacanthum hollisteri
Proximate cysts compressed to a subcircular outline. Apical polar areas always wellrounded, and without horns. Periphragm and endophragm closely appressed. Cingulum is narrow, and only weakly helicoid, it divides the epitract and hypotract into more-or-less equal halves. Sulcus extends deeply into hypotract. Tabulation is that for the genus. Precingular archeopyle apparently formed by plates 3" and 4". Plate boundaries formed by raised crests which for the most part are perforate; the perforate crests do not appear to be entirely restricted to plate margins, as they extend over the periphragm, to varying degrees, as alveolae. Periphragm covered with dense grana, and by isolated broadly tapering sharp spines. Size of twenty measured specimens from 75 to 104 µm, maximum length.