MILIOLIDAE - Acta Palaeontologica Polonica

104 EWA LUCZKOWSKA
Remarks. - This species approach morphologically to Miliolinella
circularis (Bornemann), but differs in having a quadrangular-oval test
shape, not tapering at the end, in its rough surface, covered with transverse
wrinkles, and in the broader aperture with a sickle-shaped tooth. It
resembles also M. subrotunda (Montagu), but differs in the quadrangularoval
test shape and in the tendency for its several last chambers to be
arranged in a single plane. From M. dilatata (d'Orbigny) it differs in its
more compact and higher test and more inflated chambers.
Distribution. - Poland: Upper Tortonian (Ligota Zabrska, W~glinek,
Wierzchowiska). Romania: Tortonian, Kostej in Banat.
X Miliolinella enoplostoma grammostoma (Reuss, 1867)
(pl. XX, Fig. 3a-c)
1867. Triloculina enoplostoma grammostoma Reuss; A. E. Reuss, p. 71, PI. 2, Fig. 5.
Material. - 6 specimens (ColI. No. F-157).
Dimensions: L 0.7-0.8; B 0.55-0.7; T 0.4-0.7.
Description. - Test compact, nearly circular, triangular iIi crosssection,
periphery broadly rounded; chambers inflated, with flattened
sides, broad at the base and considerably narrowing towards the end, last
chamber large, inflated, somewhat contracted at the periphery, middle
chamber oval, distinct, occupying one-third of the breadth of the front
side; sutures distinct, with slightly marked groove along the inner chamber
edge; surface smooth, polished; aperture small, semicircular with a small
semicircular flap, which is depressed in the middle.
Variability. The flattening of the last chamber periphery is variable,
which gives it its irregular, more or less triangular appearance in crosssection.
Some specimens lack the flap in the aperture.
Remarks. - The specimen figured originates from Wieliczka and
coincides with the description of Reuss, the other specimens of this species
found in Wieliczka are less regular in shape. It resembles Triloculina
austriaca d'Orbigny in morphology, but differs in the aperture with a flap.
It differs from Miliolinella valvularis (Reuss) in the marked flattening of
the last chamber periphery, as in Triloculina, and in its much smaller
aperture. The author expressed the opinion earlier (Luczkowska, 1967)
that M. enoplostoma grammostoma corresponds rather to M. valvularis
(Reuss). In fact, these two forms are very close to each other. Considering
however that in Wieliczka only a few morphologically differentiable
specimens of either species have been found, and none of the abundant
specimens of M. valvularis from other localities of the Upper Tortonian
has a flattened periphery of the last chamber, as in M. enoplostoma
grammostoma, the subspecies from Wieliczka has been retained as valid.
Distribution. - Poland: Tortonian (Wieliczka).