MILIOLIDAE - Acta Palaeontologica Polonica

MILIOLIDAE FROM MIOCENE OF POLAND 95
tubular chambers, the next 3-4 chambers have one edge, and two edges
occur only in the last whorl (Text-fig. 33/3, 4).
Remarks. - Morphologically, this species resembles Cyclojorina contorta
(d'Orbigny), but differs in its less acute and more sinuous edges, in
the less elongated, more oval test shape and in the narrow and high, not
circular aperture.
Distribution. - Poland: Lower Tortonian (Badenian), (Grabki Duze,
Korytnica). Romania: Tortonian, Kostej in Banat.
Lachlanella undosa (Karrer, 1867)
(Pl. X, Fig. 5a-c; Text-fig. 33/5, 6)
1867. Quinqueloculina undosa Karrer; F. Karrer, p. 361, PI. 3, Fig. 3.
1955. Miliolina undosa (Karrer); M. J. Serova, p. 315, PI. 7, Figs 3-6.
1961. Quinqueloculina undosa Karrer; V. J. Didkovsky, p. 24, PI. 1, Fig. 6a-c.
Material. - About 200 specimens (ColI. No. F-149, Sec. No. 165, 166).
Dimensions: L - 0.80-1.0; B - 0.5-0.65; T - 0.3-0.4.
Description. - Test broadly oval, occasionally oval-quadrangular, periphery
angular, bicarinate; chambers with concave sides, broad, with two
thick carinae on the edges, wider apart at the base than at the top, the
apertural end of the chambers being bent to the back and expanded,
middle chamber prominent, with two thick carinae, specifically curved
in the lower part, fifth chamber small, with one keel; sutures distinct,
somewhat depressed; surface smooth, dull; wall thin; aperture narrow,
high, with a long simple tooth.
Variability. Characteristic features of the species are thick distinct
carinae specifically curved in the lower part, and the expansion of the
apertural portions of the chambers. The test shape shows little variations.
Dimorphism and ontogeny. The specimens sectioned represent the
micro generation; PD 30-401l. The sections show the tubular initial chambers
followed by those with one keel, and from the 4-th or 5-th chamber
onward the edges are bicarinate (Text-fig. 33/5, 6).
Remarks. - This species is morphologically related to Lachlanella
schroeckingeri (Karrer), to which also shows ontogenetical resemblance,
but differs in having distinct thick carinae and not sinuous edges only,
in its narrower aperture and smooth surface, not covered with irregular
depressions. From L. bicostoides Vella it differs in its more slender test
shape, expanded apertural portion and higher aperture. L. collenae Vella
is very similar in test ornamentation and shape, which is however more
elongated and the carinae are acute and not thickened. L. subpolygona
(Parr) is somewhat more slender and flattened; it besides much resembles
L. undosa and may be its junior synonym or at least may be regarded
as its descendant.