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Silicisphaera
From Williams et al., 2017:
[Silicisphaera, Davey and Verdier, 1976, p. 320-321
Type species: originally as Hystrichosphaeridium ferox, Deflandre, 1937b (pl.14 (al. pl.11), figs.3–4)] ; Silicisphaera ferox, Davey and Verdier, 1976
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Original description: [Davey and Verdier, 1976]:
Description:
The cysts are spherical to ovoidal and bear one intratabular process per reflected plate area.
The processes are apparently hollow, open, or at least typically truncated distally, and are usually slightly striate or fibrous. They vary considerably in type and size on an individual although they all are of approximately equal length; they are widest, trifurcate to complex, in the pre- and postcingular regions and narrowest in the cingular and sulcal regions. The apical processes are intermediate in size; the antapical process is not distinctive or particularly large.
The reflected tabulation appears to be 4`, 6``, 6c, 5```,1p, 1```` and 0-5s.
The archaeopyle is either apparently precingular (3"), precingular (3") with an incipient separation of the apical and precingular plates or of the combination precingular 3``-apical (1-4`) type with the apical plates usually remaining attached on the ventral surface.
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Modified description:
Stover and Evitt, 1978, p. 188-189:
Synopsis:
Cysts proximochorate to skolochorate; body subspherical; paratabulation gonyaulacacean, indicated by hollow penitabular processes of essentially uniform length, but which vary considerably in type and width; distinctive antapical process absent; archeopyle precingular, Type P or combination Type tA + P.
Description:
Shape: Body subspherical.
Wall relationships: Endophragm and periphragm appressed between processes.
Wall features: No parasutural features. Penitabular processes faintly striate or fibrous, hollow, open or closed distally, of about equal length; tips truncate and variously subdivided or drawn out into tubules, and may be spinate. Processes vary widely in shape and width; those with widest and nearly equidimensional bases occur in precingular and postcingular areas. Antapical process neither distinctive nor particularly large.
Paratabulation: Indicated by penitabular processes; gonyaulacacean, formula: 4`, 6``, 6c, 5```, lp, 1````, 0-5s.
Archeopyle: Either precingular, Type P (3`` only), with orwithout an incipientapical-precingular tear, or combination Type tA + P; opercula free or adherent ventrally.
Paracingulum: Indicated by six equatorial processes with transversely elongate bases and one or more tips.
Parasulcus: Indicated by the absence of processes or by up to five single or bifurcate processes.
Size: Intermediate to large.
Affinities:
Silicisphaera, according to Davey & Verdier (1976), is characterized by large, typically complex precingular and postcingular processes and the absence of a distinctively large antapical process. Florentinia differs from Silicisphaera in having a large antapical process and less complex processes. Davey and Verdier (1976, p. 310) comment that "some difficulties may be experienced with differentiating the various species of Florentinia and Silicisphaera from one another." Consistent separation of the two genera may also be difficult.
[Silicisphaera, Davey and Verdier, 1976, p. 320-321
Type species: originally as Hystrichosphaeridium ferox, Deflandre, 1937b (pl.14 (al. pl.11), figs.3–4)] ; Silicisphaera ferox, Davey and Verdier, 1976
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey and Verdier, 1976]:
Description:
The cysts are spherical to ovoidal and bear one intratabular process per reflected plate area.
The processes are apparently hollow, open, or at least typically truncated distally, and are usually slightly striate or fibrous. They vary considerably in type and size on an individual although they all are of approximately equal length; they are widest, trifurcate to complex, in the pre- and postcingular regions and narrowest in the cingular and sulcal regions. The apical processes are intermediate in size; the antapical process is not distinctive or particularly large.
The reflected tabulation appears to be 4`, 6``, 6c, 5```,1p, 1```` and 0-5s.
The archaeopyle is either apparently precingular (3"), precingular (3") with an incipient separation of the apical and precingular plates or of the combination precingular 3``-apical (1-4`) type with the apical plates usually remaining attached on the ventral surface.
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Modified description:
Stover and Evitt, 1978, p. 188-189:
Synopsis:
Cysts proximochorate to skolochorate; body subspherical; paratabulation gonyaulacacean, indicated by hollow penitabular processes of essentially uniform length, but which vary considerably in type and width; distinctive antapical process absent; archeopyle precingular, Type P or combination Type tA + P.
Description:
Shape: Body subspherical.
Wall relationships: Endophragm and periphragm appressed between processes.
Wall features: No parasutural features. Penitabular processes faintly striate or fibrous, hollow, open or closed distally, of about equal length; tips truncate and variously subdivided or drawn out into tubules, and may be spinate. Processes vary widely in shape and width; those with widest and nearly equidimensional bases occur in precingular and postcingular areas. Antapical process neither distinctive nor particularly large.
Paratabulation: Indicated by penitabular processes; gonyaulacacean, formula: 4`, 6``, 6c, 5```, lp, 1````, 0-5s.
Archeopyle: Either precingular, Type P (3`` only), with orwithout an incipientapical-precingular tear, or combination Type tA + P; opercula free or adherent ventrally.
Paracingulum: Indicated by six equatorial processes with transversely elongate bases and one or more tips.
Parasulcus: Indicated by the absence of processes or by up to five single or bifurcate processes.
Size: Intermediate to large.
Affinities:
Silicisphaera, according to Davey & Verdier (1976), is characterized by large, typically complex precingular and postcingular processes and the absence of a distinctively large antapical process. Florentinia differs from Silicisphaera in having a large antapical process and less complex processes. Davey and Verdier (1976, p. 310) comment that "some difficulties may be experienced with differentiating the various species of Florentinia and Silicisphaera from one another." Consistent separation of the two genera may also be difficult.