38 Proceedings of the Royal Irish Academy. 
common clay of the district, with rounded and angular calp fragments, 
but of dark colour, from its saturation with animal matter; and when 
the vertical sides of the trench were freshly exposed in dry weather, 
we could notice how this covering of clay had been thrown over the 
bedies in interring them, as it assumed an appearance of stratification 
different from the homogeneous structure of the undisturbed subjacent 
yellow till. As the excavation advanced towards the east side of the 
mound, we procured several squares of sandstone, or small flagstones, 
and a few composed of split calp, averaging each about a foot square, 
that still retained marks of having been employed for fire-stones ; these 
were thrown in amongst the slain bodies, and some at least used as 
offensive weapons; thus I extracted one of these sandstone slabs 
from the place where it lay, pressing upon a skull belonging to the 
lowest layer of skeletons; it had driven the parietal bone inwards, 
breaking and depressing it. From the relative positions of this flag- 
stone and of the head, it was impossible to mistake the appearances for 
an accidental occurrence: the fracture was distinct, and the injury must 
have been sustained during life, or immediately after the person dying. 
It presented all the characters observed in a recent fracture caused by 
extreme violence, and two layers of bodies lay covering it in the 
mound. Nor was this a solitary instance of finding these stones in 
contact with human heads, to all appearance hurled upon them with 
intent to cause injuries. 
Mr. Kinahan selected for me other portions of sandstone that 
exhibited on their sides longitudinal groovings; these he ascribed to 
their having been employed for sharpening iron instruments, such as 
knives—an obvious explanation. Now sandstone is not found in or 
near the district of Donnybrook, therefore both the sharpening stones 
and the fire slabs must have been brought there; possibly they were 
obtained from the cottages of villagers residing close to the spot. Near 
some of the flagstones, and in contact with them, we got fragments 
of wood charcoal in tolerable abundance; and imbedded deep in the 
orbits of one of the most interesting and remarkable skulls that this 
excavation yielded—that of a microcephalic idiot—were numerous bits 
of this charcoal disseminated through the clay that filled its cavities. 
A good deal of charcoal was also scattered about where the flagstones 
lay, giving additional proof of wood fires having been kindled on the 
spot itself. 
In a hammer-shaped nodule of calp limestone that I have, Mr. 
Kinahan also recognised a primitive oyster-opener, such as he has 
found still in daily use along the coasts of the west of Ireland, and 
which he informs me is employed with singular dexterity by the 
natives of these districts. At one end this hammer shows the marks 
of hard usage. The flint flake itself, which possibly was used for 
kindling a fire, was also picked up by a gentleman, and given to me 
on its discovery. It was the only fragment of flint obtained in the 
mound. 
Certain marine shells were found, and require a notice. They 
