MILIOLIDAE - Acta Palaeontologica Polonica

MILIOLIDAE FROM MIOCENE OF POLAND
113
Genus Biloculinella Wiesner, 1931
+ Biloculinella labiata (Schlumberger, 1891)
(pI. XXI, Figs 8, 9)
1891. Biloculina labiata Schlumberger; C. Schlumberger, p. 556, PI. 9, Figs 60-62,
Text-figs 13, 14.
1911. Btloculina haddoniana Wright; J. Wright, p. 14, PI. 2, Fig. 22a, b; fide Catalogue
Ellis & Messina.
1957. Pyrgo haddoniana (Wright); T. Smigielska, p. 263, PI. 16, Fig. 12.
Material. - About 100 specimens (Coll. No. F-165).
Dimensions: L 0.45-1.1; B 0.35-0.9; T 0.25-0.75.
Description. - Test oval, slightly tapering at both ends; chambers
somewhat inflated, penultimate chamber narrowing and truncate at the
base, rounded at the top; chamber sides slightly sloping, narrow, of
uniform width, with narrowly rounded periphery; surface smooth,
polished; aperture broad, semicircular, nearly filled up with a semicircular
flat flape, which is somewhat inclined towards the last chamber.
Variability. The test shape is variable, being circular (PI. XXI, Fig. 8)
or oval (PI. XXI, Fig. 9).
Dimorphism and ontogeny. From Schlumberger's illustration it follows
that in this species there exist micro (p. 170, Fig. 14) and mega II? (p. 169,
Fig. 13) generations, which do not differ in morphology. The internal
structure of the micro generation is initially quinqueloculine, then cryptoquinqueloculine
and finally biloculine.
Remarks. - Schlumberger's illustrations (PI. 9, Figs. 60-62) and
text-figures of this species show a sharp and keeled periphery of chambers.
Such a keeled periphery has not been met by the author with any of the
Recent specimens, from the Adriatic and the Mediterranean Sea or in
the Miocene specimens, the shape of which is identical with that of specimens
from Recent seas. The illustration of a paratype of B. labiata given
by Loeblich & Tappan (1964, p. C 467, Fig. 355, 3-5) shows an acute periphery,
like that in Schlumberger's specimens, distinguishing this species
from the Recent and fossil specimens mentioned above. However, on the
basis of the identical shape of chambers and aperture, the Miocene specimens
have been recognized as belonging to B. labiata.
Distribution. - Poland: Tortonian (Badenian), (Gliwice Stare, Grzyb6w,
Ligota Zabrska, Wieliczka). Recent: Mediterranean Sea.
Genus Crenatella I:..uczkowska, 1972
Crenatella mira I:..uczkowska, 1972
The description and illustrations are given in Part 1.
8 Acta Palaeontologlca nr 1/74