143 
The species here enumerated are thus survivors of the more 
ancient fauna found intermingled with those characteristic of the 
later one, and where in any section the proportion of them is con- 
siderable, as at Cape Otway, its relatively low position in the 
Eocene series is probably indicated. For Spring Creek, Table 
Cape, &c., where the percentage of such forms is comparatively 
small, we hesitate to express a decided opinion, and prefer to 
wait for further evidence. In the absence of stratigraphical 
evidence, the subdivision of the Eocenes on paleontological 
grounds must be attempted with caution, the horizons apparently 
merging very gradually. It is quite possible that, like numerous 
other species known to be common to the whole series, some at 
least of those here tabulated may have existed continuously 
through the earlier and later periods. That they are either 
absent or sparingly represented in a particular deposit may 
depend upon other conditions, and notably of course upon 
geographical distance along the ancient coast line. 
We may safely affirm that a widely ditferent arrangement of 
the land and water areas formerly obtained in the Southern 
Ocean. To the north of Cape Otway there is an elevated region 
showing Mesozoic rocks only, which must have been either an 
island or a peninsula during the Eocene period, there being at 
Birregurra, Inverleigh, Shelford, Geelong, &c., on its northern 
margin a valley in which, as previously mentioned, deposits of 
the marine Eocenes occur. This valley extends to Port Phillip 
Bay and Western Port, where the high lands of the Gippsland 
Mesozoics intervene between the Tertiaries just mentioned and 
those in the east of the colony. That the Cape Otway ranges 
were separated from the mainland during the Tertiary period is 
an opinion advanced both by Mr. F. M. Krausé* and Mr. R. 
Murray. The latter gentleman further concludes that a strait 
formerly connected Port Phillip Bay with Warrnambool and 
Portland.+ 
On the coast line to the west of the Gellibrand River section no 
strictly littoral deposit of the Eocene is known either in Victoria 
or the Mount Gambier area of South Australia, the outcrops 
showing mostly deeper sea forms. These are invariably of the 
younger type, the older beds being apparently entirely absent. 
The great thickness of the newer Eocene in this region is well 
illustrated by bores lately put down in the strata at Portland, 
which failed to pierce them at a depth of 2,265 feet! The 
idea was to reach the Mesozoic strata, which were supposed to 
underlie the limestone, in the hope of finding a coal seain. 
Most probably neither the Mesozoic nor the older Eocene ever 
existed in the locality. 
* Geol. Surv. of Victoria. Prog. Rep. No. 1, page 101. } 
+ Geology and Phys. Geography of Victoria, pp. 120-1-2. 
