48 Proceedings of the Royal Irish Academy. 
duced, or at least known the use of, bronze weapons, just as at a 
much later period, and within historic times, the Scandinavian races 
were distinguished for their knowledge and free use of weapons made 
of iron. The crania of these Celts are ‘‘ better proportioned, higher, 
more globular, and approach more to the better forms of Indo-Euro- 
pean, or Caucasian skulls.” 
We notice, therefore, in Sir William Wilde’s memoir, three sepa- 
rate and distinct classes of skull found in Ireland, the Firbolg, Celtic, 
and Dane; and it was with much surprise and interest that, after col- 
lecting all the crania I could secure from the Donnybrook mound, 
and submitting them to rigid examination and the most accurate of 
all modes of testing, namely, careful measurement and calculation, 
that from the group three different varieties of crania were evolved. 
One of these—the rarest of all—was a long-headed form of skull of 
low organization, that fairly corresponds with that of a Firbolg. 
Much more numerous were the class of Celtic skulls, properly so- 
called; and in addition we had types different from both, and ranging 
themselves with those of Scandinavian origin, and with British skulls 
derived from Scandinavian ancestry. 
When studying the special osteological peculiarities of the human 
remains that were contained in this mound, I was led to consider they 
ought to afford ‘‘ humeri with perforation of the olecranon cavity,” a 
characteristic feature of less importance than the discovery of platy- 
cnemic tibiz, but still one of much interest and value for corroboration 
of the primitive period to which these bones must be referred, as it is 
a condition of bony structure which dates back as an ordinary racial 
character to the Polished Stone Period, and to that of the Dolmen 
builders, and might reasonably be expected to be found in conjunction 
with the platycnemic tibie. 
The workmen were accordingly directed to make special search 
for these missing perforated humeri, and they were at once found, as I 
expected they would be, and since that time I have obtained several 
of them; they afford us an additional point of much interest in the 
history of this discovery, and one deserving of being recorded. 
The next subject to be considered is a description of the few 
objects of archeeologic interest that were obtained in the course of the 
excavations ; and limited as their number is, they are of service in 
enabling us to form at least an approximate idea as to the probable 
age of the interments. 
The most important discovery was the Danish sword (Fig. 1): though 
broken across at the apex, and its pommel and hilt separated by the 
rusting of the middle portion of the handle, it still is in such a perfect 
condition that we can have no difficulty in recognising its distinctive 
characters. It is a broad-bladed straight double-edged weapon ; 
twenty-one inches of the blade remain attached to the hilt, and it 
measures fifty-eight millimetres transversely near the hilt, tapering 
somewhat upwards. ‘The iron hilt and pommel were found to be 
richly decorated with an inlaid pattern of gold and silver, and the 
