materials of which they are composed; and I believe that some
unaccountable gorge of waters has swept away the intervening earth,
leaving these solitary and isolated, though incontrovertible evidences,
that the summit level of all this great valley, has at one time been
where the level surface of these hills now is, two or three hundred feet
above what is now denominated the summit level."--Catlin's American
Indians, Vol. 2. pp. 11 and 12.]

[Note 35: Similar banks of fossil shells and oyster beds, are found in the
Arkansas.--Vide Catlin, Vol. 2. p. 85. At page 86, Mr. Catlin describes
banks of gypsum and salt, extending through a considerable extent of
country, and which apparently was of a very similar formation to some of
the localities I was in to the north of Spencer's Gulf.]

I have already observed that several circumstances connected with my own
personal experience have led me to the conclusion, that there is no
inland sea now occupying the centre of New Holland; it will be sufficient
to name three of the most important of these.

First. I may mention the hot winds which in South Australia, or opposite
the centre of the continent, always blow from the north, to those, who
have experienced the oppressive and scorching influence of these winds,
which can only be compared to the fiery and withering blasts from a
heated furnace, I need hardly point out that there is little probability
that such winds can have been wafted over a large expanse of water.

Secondly. I may state that between the Darling river and the head of the
Great Australian Bight, I have at various points come into friendly
communication with the Aborigines inhabiting the outskirts of the
interior, and from them I have invariably learnt that they know of no