in South Australia. 87 



found fossils which properly belong to the London clay, and 

 it would be difficult to imagine uncommon shells having so 

 wide a range as the lower Eocene in England, and the lower 

 Miocene in Australia. I have in the list of tertiary rocks 

 just detailed, omitted those beds which are found on the 

 banks of the Murray, particularly at the north-west bend. 

 I have never had an opportunity of examining these deposits, 

 but from specimens forwarded to me I think they are con- 

 temporaneous with the Mount Gambier limestones. There 

 is a great variety of nautilidce, terebratulce and pyrulce of 

 extraordinary size. I have also seen one specimen of the 

 plagiostoma spinosum of the same species as that which occurs 

 in the chalk at home. More extensive data will enable 

 future enquirers to determine the precise position of these 

 strata, and I am sure they will well repay the trouble of any 

 one who shall investigate them hereafter. 



The deposits I wish to call attention to on this occasion are 

 those already described as owing their origin to deposition 

 from a deep sea current. They are found from Lacepede Bay, 

 (as far as I have ascertained) to Bivoli Bay. Patches also 

 occur at Mount Gambier, and at some places near the mouth 

 of the Glenelg. Where they are seen most to advantage is, 

 however, at Guichen Bay ; and it is to observations made in 

 that locality, I shall confine myself more immediately. The 

 whole eastern and northern sides of Guichen Bay are com- 

 posed of low sand-hills, scarcely rising thirty feet above the 

 water level ; but on the southern side quite a change takes 

 place. The sand is replaced by rough, craggy rocks, which, 

 though not rising very high, are bold and abrupt, sometimes 

 presenting a perpendicular face to the heavy surge which 

 beats upon that coast. Seen at a distance, one would ima- 

 gine that these rocks were divided into huge strata, fourteen 

 or sixteen feet thick, but on a closer inspection, another, 

 though less distinct kind of stratification is discernible. In 

 addition to the great divisions (which are so distinct as almost 

 to lead one to suppose that three or four huge slabs of stone 

 were laid upon one another,) there is cross stratification. 

 This is a lamination which divides the beds into strata about 

 two inches thick, but they are never horizontal, like the great 

 divisions, are seldom parallel to each other, and never con- 

 tinuous across the divisions spoken of above. Now all these 

 appearances, taken in connection with the mineral composi- 

 tion which I shall just now describe, are clearly indicative of 

 deposition from an ocean current. I need not go through all 



