Fig. 64—Structure in Lepidocyclina.
A—Vertical section through test of Lepidocyclina marginata, Michelotti sp.: showing the equatorial chambers (eq. c) and the lateral chambers (l.c.)
B—Section through the median disc, showing the hexagonal and ogive chambers. × 18.
Cainozoic (Janjukian). Batesford, near Geelong, Victoria.
(F.C. Coll.)
Cainozoic Foraminifera.—
The Cainozoic strata in all parts of the world are very rich in Foraminifera, and the genera, and even many species are similar to those now found living. Certain types, however, had a restricted range, and are therefore useful as indicators of age. Such are the Nummulites and the Orbitoides of the Eocene and the Oligocene of Europe, India and the West Indies; and the Lepidocyclinae of the Miocene of Europe, India, Japan and Australia ([Fig. 64]).
The genus Lepidocyclina is typically represented in the Batesford beds near Geelong, Victoria by L. tournoueri, a fossil of the Burdigalian stage (Middle Miocene) in Europe, as well as by L. marginata. A limestone with large, well-preserved tests of the same genus, and belonging to a slightly lower horizon in the Miocene has lately been discovered in Papua.
Fig. 65—CAINOZOIC FORAMINIFERA.
