MILIOLIDAE - Acta Palaeontologica Polonica

110 EWALUCZKOWSKA
throughout, only the juvenile stage being sometimes qUinqueloculine
(Text-fig. 38/8). The chambers of juvenile stage show a broadly rounded
periphery, which becomes narrowly rounded as they grow.
Remarks. - This species differs from Affinetrina planciana (d'Orbigny)
in having distinctly flattened sides also in adult specimens, whereas in
A. planciana the periphery becomes enlarged and inflated in the course
of growth. It differs also in its much more flattened sutures, thinner
walls, and higher and narrower aperture. From A. deplanata Rhumbler
it differs in the distinctive distension of chambers near the aperture,
where they are also bent to the back.
Distribution. - Poland: Upper Tortonian (Gliwice Stare, Ligota Zabrska).
Cuba: Recent.
+ Affinetrina planciana (d'Orbigny, 1839)
(Part. I, PI. XIII, Figs 4a-c, 5a-c; Part. II, Text-fig. 38/1,2)
1839. Triloculina planciana d'Orbigny; A. d'Orbigny, in: Ramon de la Sagra, p. 173,
Pl. 8, Figs 17-19; fide Catalogue Ellis & Messina.
Material. - 80 specimens (ColI. No. F-179, Sec. No. 206, 209).
Dimensions: L - 0.6-1.2; B - 0.4-0.95; T - 0.3-0.5.
Description. - Test rhomboid-oval, irregular, tapering at both ends,
strongly inflated, periphery broadly rounded and somewhat truncate;
chambers broad at the base, narrowing upwards and broadened again at
the aperture, middle chamber irregularly oval tapering at both ends,
slightly convex; sutures distinct, depressed; wall thick; surface covered
all over with irregular short longitudinal striations giving the test its rough
appearance; aperture surrounded with a thickened rim, high and narrow,
bent distinctly to the back and filled with a long tooth slightly bifurcated
at the end.
Variability. The thickness of the test is variable, the test being nearly
square in cross-section in large specimens; then the chambers become
more inflated, the periphery truncate and the aperture widened, with
a Y-shaped tooth. The aperture of typical specimens is high and narrow.
Dimorphism and ontogeny. The specimens sectioned represent the
micro generation, PD 20~, and the mega I generation, PD 80 j.L The internal
structure of the micro generation is initially cryptoquinqueloculine,
then triloculine (Text-fig. 38/1), that of the mega I generation is irregularly
triloculine throughout (Text-fig. 38/2). The broadly rounded periphery of
chambers is kept throughout the ontogeny.
Remarks. - This species differs from Affinetrina gualtieriana (d'Orbigny)
in the higher and irregular test, more inflated chambers, depressed
sutures and broader aperture. The similarity of these species is visible in
the rough, irregularly striated surface. The recent specimens of this species
found in the materials from the Mediterranean Sea do not differ from