310 E. J. STATHAM. 
that in geologically recent times the estuary of Botany Bay has 
extended up to the high land at the Warren, and in all probability 
to that of Marrickville and St. Peters. The mere obstruction of 
tidal flow however is insufficient to account for the height at which 
the beds are found, for if the tides had unrestricted access at the 
present time they could not be covered to a greater depth than 
eighteen inches at spring tides, consequently shell fish of the same 
description as shown in these beds, could not exist under such 
circumstances, and they must formerly have been submerged to a 
greater depth which it may be possible to determine approximately 
by comparison with banks where the same description of shell-fish 
is in existence. 
At Sandringham on the open shore of Botany Bay, the 
sand brought in by the tide, has, owing to some favouring con- 
ditions as regards shelter, accumulated as a nearly level terrace, 
which has gradually grown outwards and contains abundance of 
shells, the varying characteristics of which may throw much light 
on the changes which have taken place in the molluscan life in 
the bay, and may possibly afford a time measure of some value. 
There are well defined Kitchen-middens at this place which are 
worth examination though not remarkable for size. 
The accumulations of shell at North Creek, Ballina, are the 
most remarkable and interesting of any I have examined ; that 
at North Creek Ferry, which is illustrated by Plate xiv., was cut 
through for the purpose of making an approach to the ferry four 
years since. I had the section taken at the time, and have since 
obtained a longitudinal and other cross sections (Plate xv.) from 
which the quantity of shell may be approximately arrived at. 
The antiquity of this heap is shown by the growth of trees upon 
it, some of them from four to six feet in girth and of slow grow- 
ing varieties, and also by the stratum of decayed vegetation which 
must have taken a long time to accumulate. 
The peculiar stratification of this heap is very remarkable and 
unusual, the thin layers designated ash are composed to a great 
