110 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 24,
Reuss from the Bohemian, the Westphalian, and other Cretaceous
formations, we here enumerate the ROTALINAE which D'Orbigny
figured and described in 1846 from the Miocene strata of the neighbourhood
of Vienna. And we reduce his nomenclature to that
adopted by ourselves, so that the comparison of varieties (or, rather,
in most cases, subvarieties) may readily be made by others. Were,
for instance, all the Cretaceous Planorbuline Rotalinoe figured by
Reuss, and all these Tertiary Planorbulines figured by D'Orbigny,
copied out on a sheet of paper, and arranged in the order of their
alliances, a close specific relationship would be clearly observed, but
modified by varietal and subvarietal (or rather individual) differences,
which give the groups a different fades. So also the several
Cretaceous faunas, local or successive, will be found to have somewhat
different facies, without changing much as to species and definite
varieties.
For another reason, too, have we produced this critical list of the fossil ROTALINAE from Vienna, — because the naming of these and of some of the German Cretaceous Foraminifera by Prof, Reuss was contemporaneous. It is, however, the naming of the type (or average form) of a group or subgroup that takes priority among Foraminifera, the names of minor varieties becoming merged in those of the more important types, as we have stated elsewhere.
The ' Foram. Foss. Bassin de Vienne,' is also an accessible book for most students ; and other species determined by D'Orbigny in former years can be readily found in the ' Ann. Nat. Hist.' of 1865 and 1871, in plates attached to memoirs by ourselves and our colleague Mr. H. B. Brady.
1. For the Planorbulinoe, which chiefly concern us now, it will be remembered that Pl. farcta (Fichtel & Moll) is the type ; Pl. tuberosa (F. & M.) is the subtype ; and all other known forms of Planorbulina can be grouped with one or the other of these. Or, in other words, PI. farcta may be termed the species, Pl. tuberosa the chief variety, and other forms inferior varieties of one or the other. This is zoologically true, though rather confusing. At all events, in indicating the precise relationships of the Planorbulinoe, the latter plan has to be followed. A critical account of Planorbulinoe, Pulvinulinoe, Discorbinoe, and Rotalinae, useful to the readers of this paper, will be found in the ' Phil. Trans.' 1865, pp. 378 et seq.
Rotalinae extracted from A. D'Orbigny's 'Foraminiferes fossiles du Bassin tertiaire de Vienne,' 1846.
Plate VII.
Figs. 19-21. Rotalina kalembergensis. Planorbulina, a compressed variety of Pl. tuberosa (F. & M.), near Pl. Dutemplei (D'O.), but thinner.
22-24. — — Hauerii. Pulvinulina near P. auricula (F. & M.). 25-27. — — Boucana, Pulvinulina near P. pulchella (D'O.). 28-30. — — Partschiana. Pulvinulina near P. peruviana (D'O.).
Plate VIII.
Figs. 1-3. — — D'Orbigny Partschiana. Pulvinulina near P. peruviana (D'O.), 4-6. — — Scbreibersii. Pulvinulina near P. Alvarezii (D'O.). 7-9. — — Haidingerii. Planorbulina, a conical subvariety of Pl. tuberosa (F. & M.).
