242 CENSUS OF THE OLDER TERTIARY FAUNA OF AUSTRALIA. 



and uniform ; at the Great Australian Bight the maximum 

 elevation on the coast is 250 feet, (incorrectly given in our maps 

 at 600 feet), with an increasing elevation inland for a distance of 

 80 miles ; the Muddy Creek section is 410 feet above sea level ; 

 at Gawler it is about 400 feet declining south to Aldinga Bay at 

 sea level in a length of 50 miles. Catyclismal disturbance must 

 account for the presence of fossiliferous beds of this age in the 

 Encounter Bay District at elevations above 600 feet. 



Subdivisions of the Older Tertiary. — Where the series is 

 fully developed, two distinct periods are represented separated by 

 a most decided palseontological break, and in some sections by a 

 stratigraphical one. The fossils of the older period viewed in 

 their relation to the living fauna of the same area should be called 

 Lower Eocene, if it be permiss-ible to apply European terminology, 

 whilst the younger period may be called Miocene. 



The chief fossiliferous localities of the Eocene are : — 



(1) Chalk rock and polyzoal limestone of the Great Australian 



Bight. 



(2) Inferior beds at Aldinga Bay, and River Murray Cliffs. 



(3) Mount Gambier beds ; lower beds at Muddy Creek. 



(4) Cape Otway beds. 



(5) Spring Creek, Corio Bay and Schnapper Point, 1 Cheltenham. 



(6) Table Cape, Tasmania. 



I do not attempt to correlate the sections ; though viewed 

 separately they offer very dissimilar lithological and palseontological 

 characters which might seem to indicate so many different horizons, 

 but it is not improbable the differences in the fossil assemblages 

 at different localities may have arisen from peculiar petrographic 

 and bathymetric conditions. 



Of the Miocene are : 



(1) Marbles of the Great Australian Bight. 



(2) Oyster beds Aldinga Bay and River Murray Cliffs. 



(3) Upper beds at Muddy Creek. 



(4) Moorabool River, 1 Cheltenham. 



(5) Gippsland beds. 



(6) Turritella beds, Table Cape. 



Apart from the greater affinity specifically and generically 

 which the Miocene presents to the recent fauna, its deposits are 

 characterised by the absence or paucity of Palliobranchs, Echinoids, 

 Polyzoa, Corals and Foraminifera ; and partly in consequence of 

 this, the sediments are less calcareous being for the most part 

 clays or sands. 



No marine deposits are encountered in ascending the geological 

 scale till those of Pleistocene age are reached ; the hiatus being 

 partially occupied by the Mammaliferous Drifts, which may be 

 classed homotaxially as Pliocene. 



