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Cyclonephelium intricatum
Cyclonephelium intricatum Eaton, 1971
Now Glaphyrocysta. Originally Cyclonephelium, subsequently (and now) Glaphyrocysta.
Holotype: Eaton, 1971, pl.14, fig.8
Locus typicus: Alum Bay, Isle of Wight, England
Stratum typicum: Middle Oligocene
Original diagnosis: Eaton, 1971, p. 365
The central body is typically dorso-ventrally flattened, with a sub-circular to subquadrate outline, and a finely granular surface. Processes are present on the apical and precingular zones (except the mid-ventral area), the lateral margins of the cingular zone, the postcingular zone (except the mid-ventral area), and the antapical zone. The mid-ventral and mid-dorsal areas of the central body are devoid of processes. The processes have solid, fibrous stems of variable length and breadth. Each process is distally expanded and bifurcate; the attitude of the bifurcations varies from patulate to recurved. The bifurcations are of variable length and breadth, they may be perforated, and they have a denticulate distal margin. The majority of the processes show stem fenestration and extensive branching. The branches in any one process may be distally united or free, and the total number of branches is greater than 30 in any one specimen. The archaeopyle is apical.
Dimensions: Holotype: central body (without operculum), length 43 µm, breadth 55 µm; length of processes 10-26 µm. Observed range: central body, length 38 µm (complete)-55 µm (without operculum), breadth 44-55 µm; length of processes 10-26 µm, number of specimens measured, 8.
Discussion: Eaton, 1971, p. 365: The complexity of the branching of the processes in C. intricatum prevents the determination of the precise number of processes and the reflected tabulation. The shape and ornament of the central body, and the basic form and distribution of the processes indicates a definite similarity between C. intricatum and Areosphaeridium multicornutum. The margin of the archaeopyle in C. intricatum delimits six precingular plates, and the position of the sulcal notch indicates that the plate area which is devoid of processes corresponds to 6". Plate 6" in A. multicornutum is also devoid of processes and by further comparison, the area devoid of processes in the postcingular zone in C. intricatum is interpreted as 6""". The extreme branching cf the processes frequently results in the branches being arranged in linear or arcuate complexes.
The overall form of the processes together with the fact that adjacent processes are not united distinguishes C. intricatum from all other species of Cyclonephelium. C. intricatum differs from Areosphaeridium multicornutum in having complexly branched processes, and the processes at the lateral margins of the central body are not clearly differentiated into tabulation zones.
Now Glaphyrocysta. Originally Cyclonephelium, subsequently (and now) Glaphyrocysta.
Holotype: Eaton, 1971, pl.14, fig.8
Locus typicus: Alum Bay, Isle of Wight, England
Stratum typicum: Middle Oligocene
Original diagnosis: Eaton, 1971, p. 365
The central body is typically dorso-ventrally flattened, with a sub-circular to subquadrate outline, and a finely granular surface. Processes are present on the apical and precingular zones (except the mid-ventral area), the lateral margins of the cingular zone, the postcingular zone (except the mid-ventral area), and the antapical zone. The mid-ventral and mid-dorsal areas of the central body are devoid of processes. The processes have solid, fibrous stems of variable length and breadth. Each process is distally expanded and bifurcate; the attitude of the bifurcations varies from patulate to recurved. The bifurcations are of variable length and breadth, they may be perforated, and they have a denticulate distal margin. The majority of the processes show stem fenestration and extensive branching. The branches in any one process may be distally united or free, and the total number of branches is greater than 30 in any one specimen. The archaeopyle is apical.
Dimensions: Holotype: central body (without operculum), length 43 µm, breadth 55 µm; length of processes 10-26 µm. Observed range: central body, length 38 µm (complete)-55 µm (without operculum), breadth 44-55 µm; length of processes 10-26 µm, number of specimens measured, 8.
Discussion: Eaton, 1971, p. 365: The complexity of the branching of the processes in C. intricatum prevents the determination of the precise number of processes and the reflected tabulation. The shape and ornament of the central body, and the basic form and distribution of the processes indicates a definite similarity between C. intricatum and Areosphaeridium multicornutum. The margin of the archaeopyle in C. intricatum delimits six precingular plates, and the position of the sulcal notch indicates that the plate area which is devoid of processes corresponds to 6". Plate 6" in A. multicornutum is also devoid of processes and by further comparison, the area devoid of processes in the postcingular zone in C. intricatum is interpreted as 6""". The extreme branching cf the processes frequently results in the branches being arranged in linear or arcuate complexes.
The overall form of the processes together with the fact that adjacent processes are not united distinguishes C. intricatum from all other species of Cyclonephelium. C. intricatum differs from Areosphaeridium multicornutum in having complexly branched processes, and the processes at the lateral margins of the central body are not clearly differentiated into tabulation zones.