in South Australia. 91 



the Glenelg, and as far inland as Mount Gambier, has been 

 covered with the same deep sea deposit now described, and it 

 has afterwards been removed by coast action as the land 

 slowly rose. My reasons for this opinion are founded on 

 having noticed, at various parts of the country, little hillocks 

 of rock, of small extent, and about fourteen feet in thickness, 

 so identical in composition (even to the concretions) with the 

 Guichen Bay formation, as to leave little doubt on my mind 

 of their having been continuous with it. At Mount Gam- 

 bier there is such a deposit. It is situated at a place called 

 the Cave Station. Though rather more ferruginous, and 

 containing occasionally rather larger fragments of shells, and 

 sometimes even a whole oyster shell, there can be little doubt 

 of its identity. It lies of course upon the limestones of 

 Mount Gambier, where there is every reason to believe all 

 the rest of the formation rests. The hillock now alluded to 

 has formerly been studded with concretionary pinnacles, but 

 of course much water worn, and barely jutting out from the 

 surface. What with the hardening consequent on chemical 

 action, and the ferruginous cement, the rock is almost as 

 hard as granite, contrasting strongly with the soft white rock 

 on which it rests. The hardness is doubtless the cause of its 

 preservation. Another place where a patch is seen is at a 

 station not far from the western bank of the mouth of the 

 Glenelg. In this place (to which I regret I could only afford 

 a passing examination) perfect shells are found, mostly species 

 of Astarte, Ostrea, Pecten, and Cardium. The strata, though 

 not apparently so thick, were quite as compact as those just 

 mentioned. I noticed also above the cliffs at Portland a 

 thin deposit of oyster shells. The colour and mineral struc- 

 ture of the rock in which they are, as seen from a short dis- 

 tance, seemed to me to be very like the same deposit, but 

 I would hardly venture to say that it was really such. It is 

 rather singular that it should rest upon a deposit which, if not 

 identical with the Mount Gambier Eocene, is at least very 

 close in succession. The Spatangus Forbesii occurs at both 

 Portland and Mount Gambier, and many Terebratidce and 

 Pectens are identical ; but the cellepora coral present in the 

 latter has not as yet been found in the former. This latter 

 fact may be due to local circumstances, and I have very little 

 doubt that the beds will eventually be found to be contempo- 

 raneous. 



And now having given a description of the beds at Guichen 

 Bay, their structure and other features, as well as what I 



