446 PROCEEDINGS OF SECTION C 
IJ.—Mippie TERTIARY. 
This division contains the Ostrea limestone and the upper 
deposit at Muddy Creek, the latter of which has not been 
recognised elsewhere in Victoria. The deposit at Cheltenham, 
that at Jemmy’s Point, and the superior beds of Table Cape, 
Tasmania, possess some of its characteristic forms; but though 
they all belong, probably, to the same group, none of them can 
be considered the full equivalents of this well-marked zone. 
In South Australia a group of strata, comprising the oyster 
beds of the Murray Cliffs, Aldinga, &c., has been termed Upper 
Murravian by Professor Tate, who has described fifty-two fossils 
from it. Amongst them, twenty-two are identical with Muddy 
Creek species, eight of which, or fifteen per cent., are represented 
in the lower beds, and sixteen, or thirty-two per cent., in the 
upper. The percentage of living to extinct species in the latter 
has been shown to amount to 6°5,* or much the same as in the 
Upper Murravian, where it is 5°8. It is not possible to correlate 
these two sets of strata definitely, but from the general resem- 
blance of their fossils, as well as from other considerations, they 
may be regarded as near equivalents. 
Oyster beds of considerable thickness also overlie the Older 
Tertiary, at Portland, on the Glenelg Cliffs, and in other portions 
of the counties of Normanby and Follett, but they are evidently 
younger than those on the Murray. In the neighbourhood of the 
Glenaulin Creek, at Dartmoor, and throughout the south of 
Follett, oyster shells are often turned up by the plough, while on 
the banks of the Glenelg, interesting sections of the beds are 
visible at intervals, from a few miles north of Limestone Creek 
almost to its mouth. Usually the only fossil is the prevailing 
oyster, but at Ascot Heath, near Dartmoor, several others occur, 
including numerous and fine specimens of Fecten meridionalis, 
Brazier, and AZytilus chorus, Molina (MZ. /atus, Lam.). In all, 
however, only six identifiable fossils have been found, but, as four 
of them belong to existing species, the deposit may be fairly 
classed as the youngest member of the Middle Tertiary. 
At Ascot Heath it merges gradually into the underlying 
calciferous strata, but at Portland it is sharply separated from 
the chalk rock beneath by a thin layer of rounded pebbles. Just 
as in the case of the remarkable nodule band, which divides the 
upper and lower zones at Muddy Creek, this indicates a break 
in the succession of the tertiaries, and serves as a line of 
demarcation between the older and younger groups. 
Il1.—Upprer Terriary. 
On the completion of the Ostrea Limestone deposit, a long 
interval elapsed, unrepresented in south-western Victoria by any 
* “ Notes on the Muddy Creek Beds.” Roy. Soc. S.A., 1889. 
