60 
so that the bevelled part only narrowed the natural cutting edge of the 
tooth. Some of the upper incisors, as mentioned on page 58, are also 
sharpened at an angle on the cutting edge. 
Of the fifth group, one (figure 19) is a longitudinal part of a tooth, 
sharpened about half its length from the root end, concavely on the front 
edge and convexly on the rear edge, and cut off across the natural cutting 
edge and also at the root end in a way that makes it match the other end 
as to both square tip and bevel. The root end is like that of the specimens 
in figure 16, and the cutting end like the one in figure 13. The specimen in 
figure 20 shows the inner side of a natural lower incisor of a beaver, except 
that from a point about a quarter of an inch from the natural cutting edge 
to one an inch from the root end, it has been rubbed down slightly more 
deeply in the middle so as to form a sharp angle with the outer or convex 
face of the tooth. 
One specimen from heap A is broken off at both ends, but is a longi- 
tudinal part, and is rubbed on the whole length of the artificial surface 
(figure 21). Another longitudinal piece from heap D lacks both ends, 
but shows rubbing on the section and a sharp corner where it meets the 
front or convex face of the tooth. 
Of the first group made of upper incisors, one of a beaver (figure 22) 
is broken off at the root end, gouged out at the cutting edge for about a 
quarter of an inch, and has the back or concave side of the tooth cut back 
the entire length of the object. The incisor in figure 23 has the back or 
concave wall removed from the root end to within less than a quarter of an 
inch of the natural cutting edge, exposing the natural canal of the tooth for 
over half the length of the object. The bevel of the natural cutting edge has 
been slightly smoothed. 
Of the second group, two upper incisors found in heap A lack part of 
the root end and are sharpened like others of this group made of lower 
incisors. One of this style is illustrated in figure 24, and one much like it was 
found in heap D. A piece found in heap M is broken off at both ends, but 
shows that the natural canal of the tooth was opened and that the grinding 
at one end of the canal did not taper off to form a sharp point. The grinding 
was concave in the tooth at this point, so that the tooth was left larger on 
either side of it. Two objects of this general style were found that were 
made of the upper incisors of the woodchuck, one (figure 25) in heap A 
and the other in heap D. 
Of the third group, an upper incisor of a beaver (figure 26) is a longi- 
tudinal piece of the tooth with part of the root end and all the inner or 
concave side of the section lacking, and is slightly rubbed on the whole 
length of the front or convex edge of the irregular artificial surface, except 
at the natural cutting edge. Less than a longitudinal half of an upper incisor, 
rubbed flat on the artificial surface and lacking part of the root end (figure 
27), and a fragment about an inch long of the natural cutting edge end of a 
similar specimen, were also found in heap D. 
Artificially sharpened incisors of the beaver, supposedly used as knives, 
have been found among prehistoric remains in many places. Loomis 
found them in a heap in Maine 1 . Specimens from a shell-heap in that state 
* Cf. Loomis, Fig. 5. 
