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Gonyaulacysta deflandrei*
Gonyaulacysta deflandrei (Sarjeant, 1966b, p.137–138, pl.14, figs.7–8; text-fig.35) Below, 1981a, p.53. Emendation: Sarjeant, 1982b, p.45–46, as Psaligonyaulax deflandrei.
Combination illegitimate — senior homonym: Gonyaulacysta deflandrei Riley in Fisher and Riley, 1980.
NOW Psaligonyaulax. Originally (and now) Psaligonyaulax, subsequently Gonyaulacysta (combination illegitimate). Lentin and Williams, 1981, retained this species in Psaligonyaulax Sarjeant, 1966.
Taxonomic junior synonym: Gonyaulacysta extensa, according to Clarke et al. (1968, p.181).
Holotype: Sarjeant, 1966, pl. 14, figs.7-8, text- fig.35; Jan du Chêne et al., 1986, pl.85, figs.3-4, pl.86, figs.1-3
Locus typicus: Fetchum Mill, Surrey, England
Stratum typicum: Cenomanian
Original diagnosis: Sarjeant, 1966, p. 137: Psaligonyaulax deflandrei
A Psaligonyaulax having a spindle-shaped outline, truncated posteriorly, with ovoidal inner body. Apical pericoel surmounted by bifid horn, antapical pericoel flattened. Tabulation 4", 1a, 6", 6c, 6""", 1p, 1"""". Crests of moderate height with smooth or denticulate edges. Cingulum broad, strongly spiral: sulcus narrower but widening posteriorly. Surfaces of endophragm and periphragm smooth or only minutely granular: an irregular scatter of tubecles may be present on periphragm.
Dimensions: holotype: overall length 75 µm, breadth 44 µm; length of inner body 35 µm, breadth 40 µm. Range of dimensions: overall lengths 72-82 µm, breadths 43-60 µm.
Original description: Sarjeant, 1966, p.138: Psaligonyaulax deflandrei
The apical horn is more or less conical, a bifid appearance being imparted by the apical junction of crests separating the four apical plates. Plate 1" is narrow and elongate, occupying the anterior prolongation of the sulcus; the anterior intercalary plate is also rather elongate. Six precingular and six postcingular plates are present: plate 1""" is very reduced and elongate. A posterior intercalary plate separates plates 1""" and 2""" from the single plate occupying the antapex.
The cingulum forms a laevorotatory spiral such that its two ends differ in antero-posterior position by three times its width: six cingular plates are present. The sulcus is constricted in its median portion, but widens considerably as it approaches the antapex.
The crests are in part smooth, in part denticulate: they are sometimes very finely perforate. A scatter of tubercles may be present, their number and distribution varying considerably between individuals.
Plate 3" is consistently lost in archaeopyle formation: its absence is not always obvious in unstained specimens, as a result of the delicacy and tranparency of the shell.
Combination illegitimate — senior homonym: Gonyaulacysta deflandrei Riley in Fisher and Riley, 1980.
NOW Psaligonyaulax. Originally (and now) Psaligonyaulax, subsequently Gonyaulacysta (combination illegitimate). Lentin and Williams, 1981, retained this species in Psaligonyaulax Sarjeant, 1966.
Taxonomic junior synonym: Gonyaulacysta extensa, according to Clarke et al. (1968, p.181).
Holotype: Sarjeant, 1966, pl. 14, figs.7-8, text- fig.35; Jan du Chêne et al., 1986, pl.85, figs.3-4, pl.86, figs.1-3
Locus typicus: Fetchum Mill, Surrey, England
Stratum typicum: Cenomanian
Original diagnosis: Sarjeant, 1966, p. 137: Psaligonyaulax deflandrei
A Psaligonyaulax having a spindle-shaped outline, truncated posteriorly, with ovoidal inner body. Apical pericoel surmounted by bifid horn, antapical pericoel flattened. Tabulation 4", 1a, 6", 6c, 6""", 1p, 1"""". Crests of moderate height with smooth or denticulate edges. Cingulum broad, strongly spiral: sulcus narrower but widening posteriorly. Surfaces of endophragm and periphragm smooth or only minutely granular: an irregular scatter of tubecles may be present on periphragm.
Dimensions: holotype: overall length 75 µm, breadth 44 µm; length of inner body 35 µm, breadth 40 µm. Range of dimensions: overall lengths 72-82 µm, breadths 43-60 µm.
Original description: Sarjeant, 1966, p.138: Psaligonyaulax deflandrei
The apical horn is more or less conical, a bifid appearance being imparted by the apical junction of crests separating the four apical plates. Plate 1" is narrow and elongate, occupying the anterior prolongation of the sulcus; the anterior intercalary plate is also rather elongate. Six precingular and six postcingular plates are present: plate 1""" is very reduced and elongate. A posterior intercalary plate separates plates 1""" and 2""" from the single plate occupying the antapex.
The cingulum forms a laevorotatory spiral such that its two ends differ in antero-posterior position by three times its width: six cingular plates are present. The sulcus is constricted in its median portion, but widens considerably as it approaches the antapex.
The crests are in part smooth, in part denticulate: they are sometimes very finely perforate. A scatter of tubercles may be present, their number and distribution varying considerably between individuals.
Plate 3" is consistently lost in archaeopyle formation: its absence is not always obvious in unstained specimens, as a result of the delicacy and tranparency of the shell.