MILIOLIDAE - Acta Palaeontologica Polonica

10 EWA LUCZKOWSKA
d'Orbigny for his discerning observation, since though these definitions
lack detailed data concerning the internal structure of the tests, they have
not lost their validity up to now and are used all over the world. Soon,
however, there arose difficulties in the classification of some forms which
could not be included in any of these genera, and further studies were
continued in two directions: some workers supplemented d'Orbigny's
classification by adding new genera, others concelled them and synonymized
them with other old or new taxonomic units that had a wider range
of classificatory criteria.
The first trial of overcoming these difficulties, going in the latter
direction, was made by Williamson in 1858, who integrated the forms
having their chambers coiled, two in a whorl, round the vertical axis,
together with the genera Quinqueloculina, Triloculina and Adelosina,
established by d'Orbigny, into a new genus, Miliolina. This seemingly
simplified many problems of classification and, thanks to the facility with
which the genus Miliolina could be applied for forms that differ much
from each other both morphologically and in their internal structure, it
persisted in literature for nearly 100 years. In the last century the main
followers of this trend were Carpenter, Parker, Jones, Brady, Rhumbler
and Goes. This last investigator tried even to unite all d'Orbigny's genera
in one genus, Miliola Lamarck. More detailed data concerning this page of
the Miliolidae are presented in a paper by Cushman (1917).
In the present century the direction established by Williamson was
continued chiefly by Wiesner (1912, 1918 and 1931) and Bogdanowich
(1947 and 1952). Studying the recent foraminifera of the Adriatic Sea,
Wiesner (1931) consistently used the genus Miliolina Williamson, with
which he synonymized Triloculina d'Orbigny, Quinqueloculina d'Orbigny,
Massilina Schlumberger and Sigmoilina Schlumberger. He attached great
importance to the characters of the test and grouped them according to
their significance for the determination of forms (1912). He regarded the
arrangement of chambers as the criterion of the division into larger groups,
"Formenkreise", the material of test walls, the shape of apperture and,
partly, the proloculus as the basis for the division into subgroups, and
the surface ornamentation and the presence of an arenaceous layer as the
basis for the division into "Nebenformen", of minor importace. Using
these criteria, he distinguished 4 larger groups, "Formenkreise", from
among the forms with two-chambered whorls: 1. Nubecularia Defrance,
II. Spiroloculina d'Orbigny, III. Miliolina Williamson and IV. Biloculina
d'Orbigny. Later, he (1918) somewhat changed this division, distinguishing
one larger group, Spiroloculininae, in which he included the genera
belonging to the groups separated previously: Spiroloculina d'Orbigny,
Miliolina Williamson, Articulina d'Orbigny, Adelosina d'Orbigny, Nodobacularia
Rhumbler, Biloculina d'Orbigny, Nummoloculina Steinmann,
Hauerina d'Orbigny and Ceratina Goes. In his last paper (1931) he raised