30 DR T. B. SPRAGUE ON 
battery. On my first visit, the section was, to the best 
of my recollection, of small extent; and I formed the 
opinion that the kitchen-midden was the accumulation of 
only a few years. The soil forming the top of the wall has 
now, however, weathered some three or four feet back from 
the trench, and in the section at present exposed the 
kitchen-midden extends to a length of fifteen yards. It 
is also seen to be composed of several layers, which are 
thickest in the middle, and gradually thin off to the 
extremities; these layers being separated by others of 
black soil, which are very thin in the centre of the 
kitchen-midden, but become thicker as the layers of the 
kitchen-midden become thinner. There is a thickness of from 
one to two feet of black soil above the kitchen-midden. 
The midden is composed principally of shells of the limpet 
and periwinkle, together with those of the Purpura Lapillus. 
In order to determine the relative frequency with which 
the different shells occur, I brought away a few handfuls 
which I picked up, as a fair sample of the whole; and, 
on counting, I found these contained 
18 limpets, some very small ; 
10 Purpura Lapillus ; 
75 periwinkles. 
Scattered throughout the heap are a number of bones, but 
these are very few in comparison with the above-mentioned 
shells. There are also a few fragments of crab shells, the 
red colour of which showed that the crabs had been cooked. 
In the section ‘originally exposed, there was an arrangement 
of stones,—fragments of igneous rock,—which had evidently 
formed a fire-place, the floor of which was not horizontal, 
but concave, and had probably been excavated in the soil. 
This has now disappeared through the weathering of the 
soil, but there is a long series of similar stones, flattish in 
shape, extending along the cliff. This must, I think, be 
artificial, but the object of it is not easy to conjecture. 
Possibly, when the soil was wet, these fragments may have 
been laid down in order to facilitate walking across it. The 
bones in the kitchen-midden include a great number of 
those of different kinds of birds, which have not been 
