96 EXPLORATION OF BURTON MOUND [ETH. ANN, 44 
arrowheads. As a fourth class we must regard the points that are 
triangular in section, which are clearly to be distinguished from all 
others and are chiefly of the coffee-colored material (see below). 
With these triangular-sectioned points are probably to be grouped a 
number of more irregular or poorly made specimens. A first guess 
would be that the points triangular in section are drills, but none of 
them show triations or wear such as might be produced by actual use 
in boring. 
As regards nomenclature for the various kinds of rock employed in 
making the chipped implements, it is convenient to adopt a descrip- 
tive scheme based on color, classing all varieties of flaking stone 
loosely as “ flint,” just as the Spanish Californians speak of them as 
“pedernal.” As regards the provenance of the stone, the Channel 
region abounds in pedernal of various colors and qualities. It is 
found scattered in fragments and in ledges or deposits. Even the 
beach furnishes abundant specimens. We have therefore adopted 
the following provisional scheme for classifying our chipped points. 
1. Clear obsidian. Black volcanic glass with few or no bubbles, 
quite translucent. 
2. Bubbly obsidian. Black volcanic glass full of minute bubbles. 
3. Blackish. Blackish opaque obsidian, of grayish black color, 
never coal-black. Very few specimens have a pure texture, the 
majority showing whitish flecks. In some specimens a slight banding 
can be seen, but specimens at all noticeably banded have been as- 
signed to separate classes. _ 
4. Blackish, slightly banded. The same as subdivision 3 but 
slightly banded with whitish or gray lines. 
5. Blackish banded. The same as subdivision 3 but prominently 
banded with whitish or gray lines, the light colored lines being as 
prominent as the blackish lines. The whole at a little distance gives 
a pleasing gray effect. 
6. Blackish with whitish flecks. The same as subdivision 3 with 
whitish or gray dots or flecks. 
7. Gray. The same as subdivision 3 but moderately dark gray 
color. Some specimens are banded or flecked. 
8. Dark gray. The same as subdivision 7 but darker, approaching 
the blackish type, but not so dark. Some specimens are banded or 
flecked, or have a brownish cast. 
9. Whitish gray. The same as subdivision 7 but very light. Of 
quite uniform texture. 
10. Reddish gray. The same as subdivision 7 but reddish gray. 
Distinct from the flesh-colored material. The color of some of the 
specimens might be termed raw sienna. 
11. Greenish gray. The same as subdivision 7 but greenish gray. 
Several specimens have traces of red banding. 
