OLDER TERTIARIES OF SOUTHERN- AUSTRALIA. 
355 
The fora mini t'era have been well examined by Mr. W. Howehin 
who expresses* his ability to recognise different horizons which a free 
with those now generally held, and have been based upon strati - 
graphical and molluscan evidence. 
BASIS OF CLASSIFICATION. 
All the early attempts at classifying our Tertiaries seem to have 
been based upon lithological grounds in conjunction with general 
facies. The result of such work, as would naturally be expected, 
proves upon critical examination to be inconsistent with itself, and 
this probably accounts in the main for much of the erroneous 
sequence indicated by the ages attributed to various beds in Victoria 
Sh F. McCoy furnished the list, already noted, of Tertiary fossils in 
1S71-, containing thirty-two Oligocene species, of which twenty-two 
are mollusca proper; and thirty-five Miocene species, of which nine 
are mollusca proper. Included among the twenty-two Oligocene 
species are three living shells which give a percentage of 13 : 6, and 
amongst the nine Miocene species are the names of four living species 
giving a percentage of 44‘4. This seems rather a remarkable coinci- 
dence, but it is hardly likely that such an authority as Sir F. McCoy 
would base his arguments upon such slender evidence. By taking 
these lists as they stand, and checking them in view of our present 
knowledge of the species indicated, we find that the percentage of the 
Oligocene beds reduces to five, and that of the Miocene beds°to about 
ten. Somewhat later (1870) Mr. K. A. E. Murray deplores the fact 
that the insufficiency of our paleontological evidence prohibits the 
absolute identification of the Tertiaries of this country with their 
European equivalents, and states that the terms he uses arc provisional 
ana merely intended to express the relations of the beds to one 
another. At the present time this cannot be stated, for we now know 
between 1,000 and 2,000 species from the Older Tertiaries, and 
of these quite 1,000 species are diagnostically known ; and as 
tar as the examination of the remainder has gone, it fully bears out 
and confirms the conclusions based upon the already known species. 
With such an amount of material as this, made up principally of 
mollusca, we are in a position to apply the percentage principle of living 
to extinct mollusca, as laid down by Sir C. Lyell with equal value and 
accuracy m these colonies as in Europe or America. This principle 
taken m conjunction with the stratigraphical relation and succession 
ot the beds, seems to me to be the only correct way in which to classify 
tertiary deposits. J 
As already pointed out, many seem to rely greatly upon facies, 
and this must be what Sir E. McCoy means by stating during last 
yearf that he has not yet seen any true Eocene strata in Victoria, also 
by stating m the same report J that the Geological Survey of Victoria 
may safely accept on his authority that the Muddv Creek and 
Schnapper Point beds are “of newer date than any true Eocene 
leitiary type, such as the London clay of the south-east of England, 
or the corresponing part of the basin of Paris.” Professor R. Tate has 
* A.A.A.S. Adelaide, 1893, p. 352 et seq. 
f Prog. Rep. Geo. Surv. Vic., vol. viii., 1894, p. 47. 
4 Id. p. 48. 
