MILIOLIDAE - Acta Palaeontologica Polonica

MILIOLIDAE FROM MIOCENE OF POLAND 133
Material. - About 70 specimens (ColI. No. F-184, Sec. No. 190).
Dimensions: L 0.45-0.85; B 0.27-0.5; T 0.22-0.45.
Description. - Test narrowly oval, slender, tapering at both ends,
triangular in cross-section; chambers broad, with flattened periphery and
slightly rounded edges, middle chamber slightly prominent, flat; sutures
a little depressed; surface smooth, polished; wall thin; aperture circular
with a long tooth bifid at the end.
Variability and ontogeny. The chamber periphery is flattened to
a various degree, but never quite flat. The internal structure is regularly
triloculine throughout. The specimen sectioned belong to the mega II generation,
the proloculus being 200 !J. in diameter.
Remarks. - This species is very close to Triloculina neudorfensis
Toula, but differs in its smaller dimensions, slenderer shape, flattened,
and not concave, periphery and rounded edges. It is similar to Triloculina
tricarinata d'Orbigny, differs however in its rounded, not acute, edges and
in the non-concave periphery. It corresponds most to T. angnlaris d'Orbigny,
but its edges are more rounded.
Distribution. - Poland: Tortonian (Benczyn, Bogucice, Gliwice Stare,
Karsy, Korytnica, Krywald, Ligota Zabrska, Niechobrz, W~glinek). France:
Tertiary.
Triloculina eggeri (Bogdanowich, 1952)
(PI. XXIV, Figs la-c, 2a, b; Text-fig. 45)
1952. Miliolina austriaca (d'Orbigny) var. eggeri Bogdanowich; A. K. Bogdanowich,
p. 98, PI. 5, Fig. 8a-c, cum syn.
Material. - About 300 specimens (Call. No. F-185, Sec. No. 182-187).
Dimensions: L 0.48-0.95; B 0.3-0.65; T 0.25-0.5.
Description. - Test broadly oval, narrowing at the top, roundedtriangular
in cross-section; chambers narrow with broad and slightly
flattened periphery, tapering at the end and twisted, middle chamber
convex, elongate-oval, sligthly oblique; sutures depressed, distinct, with
a narrow border along the chamber edges; wall thick; surface smooth,
polished; aperture circular, with a slightly everted border and a short
bifid tooth.
Variability and ontogeny. The breadth of chambers and their number
in the outer whorl are variable. There exist specimens with strongly
expanded chambers and a nearly triangular outline in cross-section
(PI. XXIV, Fig. la-c) and others resembling Quinqueloculina, with less
inflated chambers, of which 4-5 are visible from outside. Such 4-5­
chambered specimens represent the juvenile stage of T. eggeri (PI. XXIV,
Fig. 2a-b). In adult specimens longitudinal striae appear occasionally. The
internal structure is cryptoquinqueloculine or even quinqueloculine
initially, then irregularly triloculine. The specimens sectioned belong to