RELATIONSHIPS OF THE AUSTRALIAN CAINOZOIC SYSTEM. 
genotype of Metasqualodon, T. S. Hall. The specimens were found in 
yellow, calcareous clay on the Murray River near Wellington, South 
Australia. The molariform teeth have shorter roots than in 
Parasqualodon, this constituting the chief difference. In a remark- 
ably well-preserved tooth of Metasqualodon wilkinsoni, from Mt. 
Gambier, in the National Museum collection, the enamel of the crown 
is of a rich brown colour, and the surface covered with minute 
prickly tubercles. This example is embedded in the white polyzoal 
limestone of the locality ; the rock being in all probability equivalent 
to the yellow polyzoal limestone of Waurn Ponds and Jan Juc (Spring 
Creek). Although new genera have been instituted for these southern 
types of toothed whales, the conclusion as to their Miocene age is 
not affected thereby, as they are all members of the Squalodontidoe, 
belonging to a higher zone than the Eocene Zeuglodonts. 
Fishes. — In two papers on the Tertiary fish remains of 
Australia, published by Dr. G. P. Pritchard and myself,* the general 
distribution and range in time of each genus and species was fully 
dealt with ; but no inference was then drawn as to the ages of the 
beds yielding these remains. It is there stated (op. cit. vol. 
XVII., p. 292) that “ These data do not furnish any very clear 
evidence of our Tertiary succession and relative age of the beds, 
since the fauna has a general Tertiary aspect, but the occurrence of 
the few Mesozoic forms gives an aspect of antiquity to the older por- 
tion of our Tertiary strata.” 
The genera discussed in those papers range from Jurassic to 
Recent, and none have a restricted occurrence in Tertiary times. 
This at first sight is disappointing to the palaeontological inquirer 
for exact data of chronological value. However, looking more 
closely into the relative abundance of the genera of sharks and 
other characteristic fishes of the Tertiary, we find that all the 
abundant generic forms are especially typical of Miocene strata 
in the northern hemisphere. Amongst these may be mentioned 
Galeocerdo, Odontaspis, Lanina, Oxyrhina, Carcharodon, Lahrodon, 
and Diodon. Evidence of greater antiquity than Miocene is 
afforded by the occasional occurrence of Aster acanthus, Edaphodon, 
and Ischyodus, which appear to be the survivors in Australian 
seas of types that are elsewhere found in earlier formations. This 
is a parallel case with the occurrence of Trigonia and other forms 
of archaic life found in the same area at the present day. 
With regard to the group of the sharks, the species common to 
southern Australia and the northern hemisphere are Carcharias 
acutus f, Sphyrna prisca, Odontaspis contortidens, 0. cuspidata, 
Lamna crassidens, L. compressa, L. hronni, Oxyrhina hastalis, 0. 
* Proc. R. Soc. Viet., vol. xvii., N.S., pt. I, 1904, pp. 207-297, pis. xi., xii. Ibid, vol. xx., 
N.S., pt. 1, 1907, pp. 69-75, pis. v.-viii. 
t This determination was formed on the apical portion of a serrated tooth which nwo 
appears to belong to a recently recorded genus common to the Patagonian and Victorian 
series, viz., Carcharoides .. — See Victorian Naturalist, vol. xxx., 1913, pp. 142, 143. 
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