MILIOLIDAE - Acta Palaeontologica Polonica

84 EWA LUCZKOWSKA
Remarks. - This species differs from Cyclojorina stomata n.sp. in
having a small aperture without an everted border, narrower chambers
and a more quadrangular test shape.
Distribution. - Poland: Lower Sarmatian, (Budy, Dwikozy, Grzyb6w,
Miechocin, Mielec, Niwka, Rytwiany, Zrecze). USSR: Lower Sarmatian,
Precarpathian Foredeep.
x + Cyclojorina reticulata (Karrer, 1862)
(PI. XI, Fig. 4a, b; Text-fig. 29/1)
1862. Quinqueloculina reticulata Karrer; F. Karrer, p. 449, PI. 2, Fig. 5.
Material. - About 50 specimens (ColI. No. F-135, Sec. No. 297-301).
Dimensions: L 0.75-1.8; B 0.35-0.7; T 0.25-0.4.
Description. - Test large, narrowly oval, slender, periphery rounded;
chambers tubular, of uniform width throughout, middle chamber projecting
and large, fifth chamber usually visible; sutures distinct, depressed;
surface rough, dull, covered with a regular reticulate ornamentation,
composed of costae running obliquely in two directions and intersecting
at an angle of about 60° to make a peculiar reticulate or bifurcate pattern
along the chambers; wall thick; aperture large, circular, on a small extension
of the last chamber, and with a short, bifid tooth.
Variability. The shape of chambers and the character of ornamentation
are stable, only the manner in which the costae intersect is somewhat
variable. Some specimens show reticulation on the lower part of the
chambers only, whereas towards the end partly disappears and only the
fork-like pattern remains.
Dimorphism and ontogeny. The specimens sectioned belong to the
mega I generation, PD 60-90 ~l. The sections show rounded chambers,
regularly increasing in size (Text-fig. 29/1).
Remarks. - There are two species which are very close one to another:
Cyclojorina reticulata (Karrer) described from the Miocene of Forchtenau
in the Vienna Basin and Cyclojorina zigzag (d'Orbigny), described from
the Miocene of Buitur in Romania. According to the descriptions and
illustrations of both species, they differ only in that C. reticulata has
reticulate ornamentation, while C. zigzag has a zigzag pattern. It might
be thought that such closely related types of ornamentation represent one
species, as the extensions of zigzag lines may develop into a reticulate
ornament. A comparison of specimens investigated with the topotypes
from Buitur revealed however that there exist also other features which
support the separateness of these species, namely C. zigzag has a more
oval, compact test shape, less depressed sutures, and more densely
arranged costae (e.g. 10-15 on the middle chamber), which are strongly
oblique and make a zigzag pattern on the chamber sides only sporadically
slightly crossing each other on the periphery. On the other hand C. re-