Round the Australian Bight it continues parallel to the coast, until south of Spencer Gulf (the basal ledge still averaging 8000 ft.

Westward of South Australia, on the shores of the Australian Bight, there is a stretch of country 300 m.

Several minor ranges, the topography of which is little known, extend from Cambridge Gulf, behind a very much broken coast-line, to Limmen Bight on the Gulf of Carpentaria.

The sea encroached far on the land from the Great Australian Bight and there formed the limestones of the Nullarbor Plains.

in length unpierced by any streams, large or small, but west of the bight, towards Cape Leeuwin, some small rivers enter the sea.