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Cleistosphaeridium erectum
Cleistosphaeridium? erectum, (Manum and Cookson, 1964), Stover and Evitt, 1978
Now Kiokansium?. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Cordosphaeridium?, fourthly Cleistosphaeridium?, fifthly (and now) Kiokansium?.
Stover and Evitt, 1978, considered this to be a provisionally accepted species of Cleistosphaeridium.
Holotype: Manum and Cookson, 1964, pl.3, fig.5
Locus typicus: Graham Island, Arctic Canada
Stratum typicum: Albian-Turonian
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Original description as Hystrichosphaeridium erectum: [Manum and Cookson, 1964, p. 14]:
Description:
Shell circular to subcircular in outline with considerably more than 50 hollow appendages of slightly unequal lengths and breadths. The appendages are broadened at their bases and narrow slightly towards a whorl of three to six slender, upwardly directed processes which form approximately the upper 113 to 112 of the appendages. The processes vary in form; they may be simple and tapered towards finely pointed tips, bifurcate, or sparsely branched along their length as well as terminally bifurcate. The shell-membrane is distinctly granular and sometimes fine fibrils which radiate from the bases of the appendages can be seen on its surface.
Dimensions:
Holotype: shell 71 x 62 µm, appendages 26-32 µm long.
Range: diameter of shell 50-71 µm, overall length of appendages 13-32 µm, breadth 1-3 µm.
Affinities:
The appendages are hollow throughout, but the tubule is fine and cannot always be traced to the apex. The processes appear to be solid.
H. erectum resembles H. recurvatum (White) as described by Lejeune-Carpentier (1940) and even more its subspecies polypes Cookson and Eisenack (1962) which was distinguished on the basis of the larger number of appendages and the branched character of their processes. H. erectum has a still larger number of appendages than the subspecies polypes and their stalks are rather shorter, wider, and their processes appreciably longer and rather more branched than those of subsp. polypes. The more upright direction of the processes in H. erectum is in definite contrast to their recurved tendency in H. recurvatum and subsp. polypes.
Now Kiokansium?. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Cordosphaeridium?, fourthly Cleistosphaeridium?, fifthly (and now) Kiokansium?.
Stover and Evitt, 1978, considered this to be a provisionally accepted species of Cleistosphaeridium.
Holotype: Manum and Cookson, 1964, pl.3, fig.5
Locus typicus: Graham Island, Arctic Canada
Stratum typicum: Albian-Turonian
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Original description as Hystrichosphaeridium erectum: [Manum and Cookson, 1964, p. 14]:
Description:
Shell circular to subcircular in outline with considerably more than 50 hollow appendages of slightly unequal lengths and breadths. The appendages are broadened at their bases and narrow slightly towards a whorl of three to six slender, upwardly directed processes which form approximately the upper 113 to 112 of the appendages. The processes vary in form; they may be simple and tapered towards finely pointed tips, bifurcate, or sparsely branched along their length as well as terminally bifurcate. The shell-membrane is distinctly granular and sometimes fine fibrils which radiate from the bases of the appendages can be seen on its surface.
Dimensions:
Holotype: shell 71 x 62 µm, appendages 26-32 µm long.
Range: diameter of shell 50-71 µm, overall length of appendages 13-32 µm, breadth 1-3 µm.
Affinities:
The appendages are hollow throughout, but the tubule is fine and cannot always be traced to the apex. The processes appear to be solid.
H. erectum resembles H. recurvatum (White) as described by Lejeune-Carpentier (1940) and even more its subspecies polypes Cookson and Eisenack (1962) which was distinguished on the basis of the larger number of appendages and the branched character of their processes. H. erectum has a still larger number of appendages than the subspecies polypes and their stalks are rather shorter, wider, and their processes appreciably longer and rather more branched than those of subsp. polypes. The more upright direction of the processes in H. erectum is in definite contrast to their recurved tendency in H. recurvatum and subsp. polypes.