Figure 1: Characters measured on miogypsinids following Drooger (1952). The
illustrated specimen in A, B, and C is Miogypsinoides
cf. formosensis (image from https://foraminifera.eu
used with permission), and shows a small additional equatorial chamber (a) that
is not part of the fan of equatorial chambers (cf. chambers developed in Neorotalia).
A. chambers numbered in the primary spire with number of chambers (excluding the
protoconch [P] and the deuterioconch [D]), here X = 17. The largest chamber Z =
10 and the first chamber with two stolons that gives rise to the fan Y = 11
(these
are more subjective than determining X). B. Measurement of the angle γ: the fan of equatorial chambers is broken off, but indicated by the
white lines; angle γ
is the amount in degrees that the P-D axis needs to be rotated to 'unwind the
coil' such that D faces the apex (in this case γ
= 282°). C. Measurement of angles α and β to determine V, where V = 200α/β.
D. Measurement of the width of the protoconch Pw (including half the thickness of
the wall).