MILIOLIDAE - Acta Palaeontologica Polonica

MILIOLIDAE FROM MIOCENE OF POLAND 83
much elongated, at the basal end distinctly curved. middle chamber
convex, elongated, fifth chamber clearly visible; sutures depressed; surface
~ough, covered with numerous, very small, longitudinal depressions;
aperture at the end of a short narrowing neck and with a short bifid
tooth.
Variability. Stable characteristics of the species are the strongly
elongated test shape and tubular chambers, each of them being distinctively
curved at the base. Variation occur as a small lateral flattening of
the upper part of the chambers in some specimens, giving the test
a slightly irregular appearance.
Dimorphism and ontogeny. The specimens sectioned represent the micro
generation; PD 50 fl. The cross-sections show tubular chambers of uniform
outline, the size of which increases gradually (Text-fig. 28/2).
Remarks. - The specimens investigated correspond to the description
of Karrer, but they have a still more elongated shape than that presented
in his illustration. They are closely related to Cycloforina gracilis (Karrer),
differing only in their more elongated test shape and slightly irregular
lateral flattening of the upper part of the chambers. Le Calvez (1958)
considers C. lucida to be a form with arenaceous walls; in our specimens
from the Miocene there are no agglutinated tests.
Distribution. - Poland: Upper Tortonian (Gliwice Stare, Ligota Zabrska,
Niskowa, W~glinek). Romania: Tortonian, Kostej in Banat.
* Cycloforina predcarpatica (Serova, 1955)
(pI. XIII, 8a-c, 9a-c; Text-fig. 27/4)
1955. Miliolina predcarpatica Serova; M. J. Serova, p. 322, PI. 10, Figs 4-6.
Material. - Over 100 specimens (ColI. No. F-134, Sec. No. 364, 365).
Dimensions: L 0.35-0.40; B 0.17-0.20; T 0.13-0.15.
Description. - Test elongate, nearly quadrangular in outline, periphery
rounded; chambers tubular, inflated at the base, last chamber strongly
bent in the lower part and straightened at the end, middle chamber
elongated, inflated; sutures depressed; wall thin; surface smooth, shiny,
in some specimens delicately striated along the periphery; aperture small,
semicircular, with a slightly sloping border and a low quadrate, somewhat
bifid tooth.
Variability. The test shape varies somewhat, being elongate, oval or
broadly oval. On the periphery of some specimens appear longitudinal,
fairly regular striae, which makes them similar to Cycloforina fluviata
(Venglinsky), from which they however differ in the less inflated basal
part of their chambers and in lacking distinct ridges on the periphery.
Dimorphism and ontogeny. The sections show about 8 semicircular
chambers of uniform shape and slightly increasing in size as added;
PD 20 f.l (Text-fig. 27/4).