OBSERVATIONS ON SHELL-HEAPS AND SHELL-BEDS. ole 
described by Mr. Etheridge, from a collection made by Mr. 
Wilkins, particulars of which are published in the Mining Report 
of 1891, page 267, and I have a list of twenty-seven specimens of 
characteristic living shell, collected by myself on the North Coast 
and determined by the same authority, but not one of them in 
Mr. Wilkins’ list is represented in the latter, which however, not 
being strictly local may be merely accidental, it nevertheless shows 
that. a more careful comparison may throw much light on the 
subject. 
Among the accumulations at Ballina Pilot Station, I noticed 
considerable quantities of Nodular-Pumice, this is to be found in 
the shell heaps at Ballina Cemetery, and high up on the hill in 
shell deposit near Mr. Fenwick’s residence ; this suggests another 
possibility with regard to these deposits, namely, that they are 
contemporaneous with the period of volcanic activity, the traces 
of which are so abundant in that locality, and if Mr. Wilkins was 
right in attributing the origin of these accumulations to the 
aborigines it would assign a high antiquity to the race, or else 
bring down the volcanic period to very recent times. I wish it 
however to be distinctly understood that I do not attempt to 
assign a time either for this or the past duration of the aboriginal 
race; my observations have no special reference to a determin- 
ation of this sort and are deficient in that thoroughness which 
would be necessary in such an investigation ; the data moreover 
for the exact calculation of the quantities in the heap (rough 
estimate of which is given) are not su flicient for this purpose, but 
serve to show that valuable results may be looked for if a more 
detailed and systematic investigation is undertaken. After 
determining which are natural and which are artificial deposits, 
the first essential would be to trace the position and extent of the 
old shell banks from which the heaps are derived and the area of 
gathering ground they afford at a depth not exceeding four feet. 
Then the Fisheries Department may be in a position to state or 
ascertain the maximum and average yields per acre of the beds 
already worked, so that by this means co-efficients may be arrived 
