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Cyclonephelium semitectum
Cyclonephelium semitectum Bujak in Bujak et al., 1980
NOW Glaphyrocysta. Originally Cyclonephelium, subsequently (and now) Glaphyrocysta, thirdly Riculacysta (combination not validly published). Taxonomic senior synonym: Riculacysta perforata, according to Köthe (1990, p.50) - however, Kirsch (1991, p.129) retained Cyclonephelium (as Riculacysta, now Glaphyrocysta) semitectum. Age: Mid Eocene (see Aubry, 1986).
Original diagnosis: Bujak et al., 1980, p. 46
Cysts with spherical to ovoidal central body which may have two antapical lobes. Central body surface granulate or reticulate. Simple fibrous processes arising from the central body periphery and two of the ventral precingular paraplates, support a perforate membrane. The membrane is present around the dorsal side of the cyst and is absent from most of the ventral side. It arises from a subquadrate middorsal area, where it is in contact with the central body. The height of the membrane is greatest antapically and lessens progressively towards the apex. The ventral border of the membrane is entire and occurs near the processes. The membrane rises from the anterior border of the dorsal zone of contact and forms a striate flange which extends anteriorly beyond the archaeopyle suture, terminating in a straight or undulating entire margin. Additional small simple ventral processes may be present and are distally free. No dorsal precingular processes were observed. The archaeopyle is apical, tetratabular. The operculum has up to four processes and a high perforate distal membrane.
NOW Glaphyrocysta. Originally Cyclonephelium, subsequently (and now) Glaphyrocysta, thirdly Riculacysta (combination not validly published). Taxonomic senior synonym: Riculacysta perforata, according to Köthe (1990, p.50) - however, Kirsch (1991, p.129) retained Cyclonephelium (as Riculacysta, now Glaphyrocysta) semitectum. Age: Mid Eocene (see Aubry, 1986).
Original diagnosis: Bujak et al., 1980, p. 46
Cysts with spherical to ovoidal central body which may have two antapical lobes. Central body surface granulate or reticulate. Simple fibrous processes arising from the central body periphery and two of the ventral precingular paraplates, support a perforate membrane. The membrane is present around the dorsal side of the cyst and is absent from most of the ventral side. It arises from a subquadrate middorsal area, where it is in contact with the central body. The height of the membrane is greatest antapically and lessens progressively towards the apex. The ventral border of the membrane is entire and occurs near the processes. The membrane rises from the anterior border of the dorsal zone of contact and forms a striate flange which extends anteriorly beyond the archaeopyle suture, terminating in a straight or undulating entire margin. Additional small simple ventral processes may be present and are distally free. No dorsal precingular processes were observed. The archaeopyle is apical, tetratabular. The operculum has up to four processes and a high perforate distal membrane.