Chytroisphaeridia pericompsa, (Ioannides et al., 1977), Davey, 1979

Holotype: Ioannides et al., 1977, pl.5, fig.1
Locus typicus: Clavell's Hard, Dorset, England
Stratum typicum: Kimmeridgian

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Original description as Tapeinosphaeridium pericompsum: [Ioannides et al., 1977, p. 463]:

Diagnosis:
Shell spherical to elongate, smooth thin-walled.
Tabulation absent.
Cingulum and sulcus not observed.
A precingular archaeopyle usually present.

Description:
Shell smooth, thin, one-layered. A precingular subtriangular to subpolygonal archaeopyle usually present. Secondary folds running on or parallel to periphery always observed.

Dimensions:
Range: shell length 40-88 µm, breadth 38-85 µm (45 specimens measured).

Affinities:
It differs from Chytroeisphaeridla chytroeides Sarjeant, 1962, in the position of the archaeopyle being apical in the latter species.