174 R. ETHERIDGE, T. W. E. DAVID, AND J. W. GRIMSHAW. 
tomahawks were found in the first sump hole ata point opposite 
the middle of the dam, and one to the south-west, at the present 
site of the pump. Recently a third was found in a heap ‘of mullock 
on the bottom of the canal on south-east side of the same dam. 
The two tomahawks from the first sump were six feet below low 
water, and therefore eleven feet below mean high water mark. 
One of these has come into our possession, and differs in no way 
from the oblong ovate type used by the aborigines, and is now 
exhibited. 
(6) What appears to be a far more interesting piece of evidence 
of man’s presence around Botany Bay at this epoch of its history 
is afforded by the Dugong bones, particularly the ribs. Many of 
these are scarred transversely and obliquely with deep scratches 
and cuts, especially at their distal ends. These incisions are most 
certainly not of recent execution, nor can we conceive any fortu- 
itous circumstances, such as contact with sharp rock surfaces, 
that would produce them. They present the appearance of cuts 
and scratches that would be made by the direct blows of a sharp- 
edged stone tomahawk. The cuts are in themselves curved, with 
the central portion deeper than the sides, such as one would expect 
to be caused in the manner suggested. (See Plates 10, 11.) The 
esteem in which the Dugong’s flesh was held by the blacks of the 
north-east coast is well known, and has been already referred to, 
and we are informed by Mr. R. Grant of the Australian Museum, 
that he has seen Dugong bones on the Queensland coast, with 
similar markings, that he knew had been handled by the abori- 
gines. There is, therefore, the probability that at the time this 
Sirenian was stranded, and before the final geological changes had 
taken place that brought about the present aspect of the Botany 
and contiguous swamps, man was an inhabitant of the locality. 
One other item of evidence there is—the burnt off stumps in the 
forest bed, although this is of a much less conclusive nature. 
(6) The Submerged Forest.—As already mentioned, a very large 
number of stumps of trees were found, chiefly just to the south- 
-west of the northern dam. The greater number of these were in 
