292 T. W. E. DAVID. 



shut off on the south-east by a- continental area of Palaeozoic 

 and Lower Mesozoic rocks extending from the Gawler Ranges to 

 Mount Lofty and through the Barrier Ranges to Cobar and thence 

 to the Cordillera of New South Wales. The only other direction 

 by which the Cretaceous Ocean extending southerly from tha 

 Gulf of Carpentaria might have joined the Southern Ocean would 

 have been by way of Lake Eyre, extending to the south of the 

 Musgrave Ranges and lying to the west of the Gawler Ranges. 

 On the east this ocean was bounded in the Australian area by the 

 present main line of water-parting between the sources of the 

 Flinders, Thompson, JBarcoo, Warrego, Condamine and Darling 

 (or Barwon) Rivers, and by the foothills on the edge of th& 

 Western Plains of New South Wales from near the Queensland 

 border as far south as Narromine. The western boundary of this 

 ocean is not known, but it was probably shut in by the Cloncurry 

 and Musgrave Ranges and areas of rocks older than the Cretaceous 

 extending from the latter locality to some point between Eucla 

 and Cape Arid. 



Mud springs or mound springs exist over a large portion of the 

 area once occupied by this Cretaceous Ocean. The principal 

 localities known to me are as follows : — 



New South Wales — Wee-Watta, Cuddie Springs, Mulyeo. 



Queensland — Several remarkable groups on the Lower Flinders; 

 on the Einasleigh River ; and between Hungerford and Thargo- 

 mindah. 



South Australia — In numerous spots over the great low-lying 

 plain, into which drain the rivers Diamentina, Cooper, Macumba 

 and Neales, and within which lie Lakes Eyre, Blanche and Frome. 



Victoria — It is doubtful whether any natural mound springs 

 exist in this Colony, though the Author is informed by Mr. H. 0. 

 Russell, f.r.s., the Government Astronomer of New South Wales, 

 that it has been reported to him that the water, which usually lies 

 in the extinct craters of Lake Albert and Lake Leake, near the 

 boundary of Victoria, in South Australia, occasionally undergoes 

 variations of level, which are independent of evaporation, or of the 



