26 
must have arisen in manipulating such small specimens as d 
and y, tablet 8. 
Upon tablets lo and 13 are shown flint-flakes which have been 
carefully chipped upon the upper surface, the under surface 
being unworked. Similar specimens are exhibited from York- 
shire, in Case B 22, tablets 18 to 20. 
Flint spear-heads and implements are shown upon tablets 14 
to 19. 
Flint cores, or nuclei (blocks from which flakes have been 
removed) are shown on tablet 22. Flint tools which have 
been used for scraping are shown on tablet 23 ; ^ is much worn. 
A disc of flint a is shown on tablet 20. Similar flint discs from 
Yorkshire are shown in Case B 21, tablet 27, and an obsidian 
disc from Mexico, Case B 30, tablet 12 d\ b, tablet 20, is a 
flint scraper. 
B 24. 
Stemmed Flint Arrow-heads. 
Stemmed flint and stone arrow-heads are shown on tablets i 
to 21. Sir William Wilde's ''barbed" arrow-heads are included 
with his "stemmed" class in this series. The specimens e, 
tablet 16, and tablet 19, are much patinated ; f, tablet 10; 
e, tablet 11 ; a, b, and c, tablet 13 ; and e, tablet 15, are serrated 
at the edges. 
The arrow-head c, tablet 1 8, is indented on both sides, as if 
to afl"ord greater security in fastening it to the shaft. For modern 
illustrations of the mode of attaching flint and obsidian arrow- 
heads to the shaft by the Pimo Indians, living on the banks of 
the Gila river in Arizona, about 130 miles from the Colorado 
river of California, see Case E 3, Nos. 16 to 24 and 43 to 50. 
In Case E 3, Nos. i to 5 are examples of stemmed flint 
arrow-heads attached to the shaft in recent use by the Esquimaux 
of Behring's Straits. 
B 25. 
Leaf-shaped Flint Arrow-heads. 
Leaf and lozenge-shaped arrow-heads are shown on tablets 
I to 16; the surface chipping upon some of the specimens is 
remarkable, see b and c, tablet i ; /, tablet 2 ; all upon tablet 4 ; 
and a and b, tablet 5. Some of the specimens were artificially 
rubbed, after having been chipped, such as a, b, d, and tablet 7, 
and a, tablet 8. Upon tablet 19 is a flint spear-head. 
In Cases B 23 to B 25 many flint flakes will be noticed 
