MILIOLIDAE - Acta Palaeontologica Polonica

116 EWA LUCZKOWSKA
Remarks. - The topotypes from Wieliczka have not an acute process
at the base, like that figured by Reuss (op. cit., PI. 49. Fig. 5). On the
contrary, the lower edge of the test is truncate and parallel to the aperture
edge. The form illustrated by Reuss was probably an atypical one, or the
spine at the base was a part of the apertural tooth left after the removal
of the last chamber. The variety "platystoma" distinguished by Reuss
(1867, PI. 1. Fig. 8.) and Pyrgo larvata (Reuss) which was found in
materials from Wieliczka only in the form figured in PI. XXII, Fig. 8
of this paper, lie within the variation range of P. amphiconica. This species
differs from P. lunula (d'Orbigny) in the more inflated test, much narrower
chamber sides, narrower slitlike aperture, and low and broad tooth.
The topotypes of P. lunula from Baden (Austria) are actually more
flattened and have broader chamber sides and a considerably smaller
aperture. It is not clear, however, if these characters are not ones of
juvenile P. amphiconica, because such juvenile specimens of P. amphiconica
may be found in materials from Wieliczka (PI. XXII, Fig. 7.). Owing
to the scarcity of the material from Baden available it is not possible to
decide the problem.
Distribution. - Poland: Tortonian (Gliwice Stare, Wieliczka).
+ Pyrgo clypeata (d'Orbigny, 1846)
(Pl. XXII, Fig. 2a, b; Text-fig. 39/4)
1846. Biloculina clypeata d'Orbigny; A. d'Orbigny, p. 263, PI. 15, Figs 19-21.
Material. - About 100 specimens (ColI. No. F-169, Sec. No. 435).
Dimensions: L 0.55-1.3; B 0.4-1.1; T 0.3-0.9.
Description. - Test broadly oval, ~lightly tapering towards the aperture,
narrowly oval in cross-section; chambers moderately inflated, arcuate
in cross-section, lower part of penultimate chamber extended downwards
and truncate, chamber edges, rounded, chamber periphery fairly broad,
widened at the base, and nearly flat; sutures distinct, not depressed; surface
smooth, polished; aperture semicircular, small, slightly prominent,
with a transverse quadrangular tooth and small lateral processes.
Variability and ontogeny. Only the shape of the test, oval or more
rounded, is variable. The characteristic feature of the species are nearly
flat chamber sides, which are expanded at the bottom. The specimen
sectioned belongs to the mega I generation; PD 110,.... The internal structure
is biloculine throughout (Text-fig. 39/4).
Remarks. - From Pyrgo (Biloculinella?) affinis (d'Orbigny, 1846) this
species differs in its quadrangular, not arcuate, tooth and more flattened
test.
Distribution. - Poland: Tortonian (Benczyn, Gliwice Stare, Grzyb6w,
Karsy, Korytnica, Krywald, Ligota Zabrska, W~glinek, Wieliczka). Austria: