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Hystrichosphaeridium parvum
Hystrichosphaeridium parvum Davey, 1969
Holotype: Davey, 1969, pl.2, fig.1
Age: ?Campanian-Maastrichtian
Original description (Davey, 1969)
Derivation of name: Latin, parvus, small - with reference to the small size of this cyst.
Diagnosis: Cyst of small size possessing a smooth to lightly punctate test wall. Processes typically tubiform, all of approximately the same length, with serrate distal margins; they are of variable width and may be joined laterally by membranes. Apical archaeopyle typically present.
Holotype: Bernard Price Insititute Colln. slide ZU3/C7. Upper Cretaceous (Campanian?/Maastrichtian).
Dimensions: Holotype central body diameter 10 by 21 µ, length of processes 5-7 µ. Range, central body diameter 16(20.3)23µ, maximum length of processes 4.5(7.0)8µ. Number of specimens measured, 8.
Description: The processes are tubiform, widening distally and terminating with a denticulate or serrate margin. The width of the processes varies considerably on an individual, form 1 to 4µ. Rarely some of the processes are linked by connecting membranes which extend along the entire length of the processes. The processes are arranged in a circular manner around the test and are 20 to 25 in number. The antapical process is sometimes distinctively broad.
Remarks: H. parvum sp. nov. is similar to H. patulum Davey & Williams (1966b) in size and in the overall form of the processes. The processes of the latter species are, however, greatly expanded distally, with an entire margin and may be divided into two types. Hystrichosphaeridium sp. A, as described by Drugg 1967, differs in the possession of furcate closed processes and ridges on the central body wall. The presence of membranes connecting the processes of some specimens of H. parvum gives them a Cymatiosphaera-like appearance.
Holotype: Davey, 1969, pl.2, fig.1
Age: ?Campanian-Maastrichtian
Original description (Davey, 1969)
Derivation of name: Latin, parvus, small - with reference to the small size of this cyst.
Diagnosis: Cyst of small size possessing a smooth to lightly punctate test wall. Processes typically tubiform, all of approximately the same length, with serrate distal margins; they are of variable width and may be joined laterally by membranes. Apical archaeopyle typically present.
Holotype: Bernard Price Insititute Colln. slide ZU3/C7. Upper Cretaceous (Campanian?/Maastrichtian).
Dimensions: Holotype central body diameter 10 by 21 µ, length of processes 5-7 µ. Range, central body diameter 16(20.3)23µ, maximum length of processes 4.5(7.0)8µ. Number of specimens measured, 8.
Description: The processes are tubiform, widening distally and terminating with a denticulate or serrate margin. The width of the processes varies considerably on an individual, form 1 to 4µ. Rarely some of the processes are linked by connecting membranes which extend along the entire length of the processes. The processes are arranged in a circular manner around the test and are 20 to 25 in number. The antapical process is sometimes distinctively broad.
Remarks: H. parvum sp. nov. is similar to H. patulum Davey & Williams (1966b) in size and in the overall form of the processes. The processes of the latter species are, however, greatly expanded distally, with an entire margin and may be divided into two types. Hystrichosphaeridium sp. A, as described by Drugg 1967, differs in the possession of furcate closed processes and ridges on the central body wall. The presence of membranes connecting the processes of some specimens of H. parvum gives them a Cymatiosphaera-like appearance.