25 
Nos. 8 to lo). No. 20, however, is possibly merely a fragment 
of some larger implement. 
Upon tablets 24, 25, 26, 27, and 28 are worked flints of 
undetermined use. 
B 22. 
All the specimens in this Case are from Yorkshire, and chiefly 
from Bridlington. 
Upon tablets i to 5, 9, 10, and 15 are leaf-shaped flint arrow- 
heads. 
Upon tablets 6, 7, and 8 are triangular flint arrow-heads. 
Some archaeologists think that such specimens as a, tablet 8, were 
used for knives. 
Upon tablets 15 and 16 are stemmed flint arrow-heads. 
Upon tablets 11 to 14 are flint tools, many of which have 
been used for drilling, and show wear. — See tablet iz c. 
Upon tablets 18 to 20 are flint flakes, quite unworked upon 
the under side, but carefully chipped upon the upper surface. 
Upon tablet 21 are flint spear-heads. 
Upon tablets 25 to 28 are flint implements which only show 
traces of wear at the points, and which may have been used 
for flaking flint by pressure^ in contradistinction to the process 
of flaking it by percussion in the ordinary way. 
The specimens on tablet 8 exhibit such parallel flaking (ripple 
work) that it is difficult to believe it possible to remove flakes 
with sufiicient precision by blows given with a hammer or other 
tool. 
The modes of flaking, both by pressure and by percussion, are 
practised in modern, no less than they were in ancient times. 
Flint and Stone Hatchets, Arrow-heads, and Implements 
FROM Ireland are exhibited in Cases A 22 to A 27, 
and B 23 to B 25. 
B 23. 
Triangular Flint Arrow-heads. 
Triangular flint and stone arrow-heads are shown on tablets 
I to 9. It will be observed that Sir William Wilde's two first 
classes of arrowheads are included in this series — the triangu- 
lar," and the triangular hollowed out at the base." 
Attention is directed to the fineness of the surface chipping 
upon many of these specimens — such as e, tablet 8 ; to the 
serration of edge, as in i, tablet 5 ; to the extreme correctness 
of outline, as in tablet 3 ; and to the great difficulty which 
