MILIOLIDAE - Acta Palaeontologica Polonica

42 EWA LUCZKOWSKA
largest, those of megalospheric II generation are smaller and the forms
of the megalospheric I generation are the smallest. The proloculus
diameters are: microspheric - 20 fl, megalospheric 1-50-120 fl megalospheric
II - 220-270 fl.
1mm
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a
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I
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Fig. 9. Quinqueloculina anagallis sp. n., Lower Tortonian, Karsy; MS micro generation;
a front view, b apertural view, c cross-section.
Ontogeny. - There are intermediate forms between the quinqueloculine
and massiline stage. Particular stages of development observed in
cross-sections show that the size of test is dependent on that of the proloculus
rather than on the number of chambers. The specimens of the
same size suggest that the larger the proloculus the fewer the chambers
and vice versa, the smaller the proloculus the greater the number of
chambers. The formation of the massiline stage in the megalospheric I generation
begins after at least six chambers (besides the proloculus) of the
quinqueloculine stage have been built. Next chambers are added in planes
of coiling ,..... 180 0 apart, giving a slightly sigmoiline line in sections
(Text-fig. 8/1). The formation of the massiline stage in the megalospheric
II generation commences as early as 3-4 chambers of juvenile stage have
been built and it proceeds in a slightly sigmoiline manner as well; the
adult specimens possess about 4 chambers of massiline stage (Text-fig 7/1).
Thus they are a good example of the partial reduction of the juvenile
stage in connection with the reproductive cycle. The microspheric generation
has about 20 chambers of quinqueloculine stage initially and only
the last 3-4 chambers are massiline (Text-fig. 9). The juvenile specimens
of massiline stage of the megalospheric I generation differ from those of