Notices of Memoirs — Sequence of Australian Tertiaries. 515 



allocating these beds to the well-known horizons of the northern 

 hemisphere as are percentages of living forms in these fossil deposits. 

 The percentage method can only be used with safety as an approxi- 

 mate guide to age, seeing the difficulty of obtaining an agreement 

 amongst zoologists as to what constitutes a species. 



The above series of European divisions correlated with the Australian 

 corresponds almost exactly with McCoy's original determinations, 

 augmented by observations on faunas and stratigraphic relationship 

 of the beds made by the writer during twelve years' attention to this 

 subject. 



Sequence of the Beds. — With regard to the sequence, some Victorian 

 authors hold the opinion that the Janjukian Series is older than the 

 Ealcombian ; but the confusion seems to have arisen from the 

 occurrence of a large number of persistent species, especially of 

 ilollusca, passing up from the argillaceous Balcombian into the 

 Janjukian Clay Series. Where faunistic and stratigraphic relationships 

 were both doubtful the term Barwonian was suggested, which included 

 both Balcombian and Janjukian. If, howevex", we regard the scope 

 of the Janjukian in its broad sense as embracing all phases of sedi- 

 mentation, of one long time series, the term Barwonian is no longer 

 needed, its members being included in the term Janjukian. The 

 sequence of the beds 1, 2, and 3 as given here has lately been 

 established by the author from evidence obtained in cliff-sections at 

 Muddy Creek near Hamilton, and in the bores put down in the Mallee 

 and at Sorrento. 



Other authors since McCoy agreed as to the present sequence, but 

 differed in regard to the age of the oldest beds, which they held to 

 belong to the Eocene, making the succeeding beds correspondingly 

 older. 



Giiide Fossils. — The various members of the Australian Kainozoic 

 system have been referred by the writer to the horizons given above, 

 chiefly through a study of the Cetacean types, the fish remains, the 

 Mollusca, the Polyzoa, the Ostracoda, and the Foraminifera. In the 

 oldest beds (Balcombian) a predominant fossil is Amphistegina, long 

 mistaken for Nummidites variolaria, the latter genus in reality being 

 absent. In the limestone phase of the succeeding Janjukian beds the 

 Miocene type of toothed whale, Parasqualodon, occasionally occurs; 

 in the marls the Miocene genus Spindirostra; whilst the Burdigalian 

 forms of Lepidocyclma are abundant in the polyzoal series of the 

 Janjukian. In the Kalimnan Series, Cetacea, known elsewhere in the 

 Pliocene Crag (Diestian and Astian) of Antwerp and England as 

 Scaldicetus and the ziphioid whales, are characteristic fossils. The 

 above interpretation of the Australian Tertiary sediments agrees also 

 with the data acquired by Australian physiographists, and is that 

 generally accepted for j^ew Zealand and Patagonia. 



Terrestrial Series. — The terrestrial Tertiary deposits, so far as they 

 are known, are assigned to the various horizons as follows : — 



Balcombian. — Leaf-beds of Mornington and the brown coal of the 

 Alton a Bav Coal-shaft. 



Janjukian.— Leaf-beds of Sentinel Eock (Cape Otway), Haddingley 

 near i3acchus Marsh, Pitfield Plains, Narracan, Dargo High Plains, 



