The siliceous valves of freshwater diatoms constitute the infusorial earths of Victoria, Queensland, New South Wales and New Zealand. The commonest genera met with are Melosira, Navicula, Cymbella (or Cocconema), Synedra, Tabellaria, Stauroneis and Gomphonema. They are, generally speaking, of Pleistocene age, as they are often found filling hollows in the newer basalt flows. In Victoria diatomaceous earths are found at Talbot (See Fig. 42), Sebastopol and Lancefield; in Queensland, at Pine Creek; in New South Wales, at Cooma, Barraba, and the Richmond River; and in New Zealand at Pakaraka, Bay of Islands. In the latter country there is also a marine diatomaceous rock in the Oamaru Series, of Miocene age.
COMMON OR CHARACTERISTIC FOSSILS OF THE FOREGOING CHAPTER.
Girvanella problematica, Nicholson and Etheridge. Cambrian: S. Australia.
Bythotrephis tenuis, J. Hall. Silurian: Victoria.
Haliserites Dechenianus, Göppert sp. Silurian and Devonian: Victoria.
Cordaites australis, McCoy. Upper Devonian: Victoria.
Lepidodendron australe, McCoy. Lower Carboniferous: Victoria and Queensland. Up. Devonian: New South Wales.
Rhacopteris inaequilatera, Göppert sp. Carboniferous: New South Wales.
Glossopteris Browniana, Brongniart. Carbopermian: New South Wales, Queensland, Tasmania and W. Australia.
Gangamopteris spatulata, McCoy. Carbopermian: Victoria, New South Wales and Tasmania.