70- ON THE TERTIARY DEPOSITS OF AUSTRALIA. 
the employment of such terms as oligocene, miocene, &c. This 
Professor Duncan has pointed out, and has suggested the employ- 
ment of the word cainozoic as a general term to distinguish 
those lower tertiary beds which contain the commencement of 
our modern fauna or new life. While quite agreeing with the 
learned professor in this, my long acquaintance with all the 
tertiary formations and my familiarity with the fossils induce me 
to offer a few suggestions which I think may carry our know- 
ledge a little further. If we cannot apply the percentage system, 
e can, at least, form general conclusions from superposition, 
distribution, &e., as to the chronology of the series—if I 
speak. And m 
oa 
fauna of widely separated seas, which have scarcely any 
ommon, ve a resemblance, in the 
onal of certain genera in certain habitats. Thus I 
Suppose there are no seas where some forms of Littorina, 
Patella, Trochus, peer ae Cardium, Pectunculus, and Mytilus 
do not inhabit the rocks a sands. And some of the species het 
so close a general cosine that it is only after a careful com- 
arison we can sée specific differences. Now, we ought to see a 
we go further back in time, so we a wider range for species, 
until in the earliest deposits we find little specific variety all over 
the-world. Iti is es quite so certain, however, that where wide- 
p ver specific identity oo fil, rb close affinity s 
ows 
mo rovinces, all united ng one general Australian foes 
yet all with distinct characters pec eculiar to each. To 
the ° 
eri net shee i Eucla to Cape Leuwin. Now each of 
these provinces cies of its own and ies in common. 
Observation as yet will not permit us so far to say with certainty 
how many of the species now identified are no more an local 
varieties. However, we can be certain that for ‘hike species 
