BY C. W. DE VIS, M.A. 45 
surface, but the expansion of the tooth below it is repre- 
sented in the fossil by a thickening of the enamel only. 
The cutting edge of the tooth is narrow and curved, the 
dentine behind it, exposed by attrition, elongated fore and 
aft. Like the crown, the fang gradually contracts in 
all its dimensions, it is much compressed transversely, the 
middle of each of its broad sides is concave, and its anterior 
edge forms a regular curve, continuous with that of the 
crown. The total length is 78 mm., of which the crown is 
38 mm.; the fore and aft depth is 20 mm., nearly ; its 
greatest transverse measurement, 11 mm. A second speci- 
men, which has lost the crown from above the inner fork of 
enamel, had a length, when complete, of about 112 mm., or 
nearly 44 inches. 
The second upper incisor is represented by a tooth from 
each of the sides and a second of the right side. The crown 
of this tooth greatly resembles that of the corresponding 
incisor of Dicotyles. On the posterior side it has the extero- 
inferior tubercle and the intero-superior tubercle and 
groove, but the latter is continued upwards to the summit, 
over which it passes to the posterior surface; a survival of 
this continuity is extant in Dicotyles. On the outer side 
the lateral tubercle is strongly demarcated from the 
adjacent surface by a depressed elongated area. This is 
reduced in Dicotyles to a linear groove. The edge of the 
tubercle is entire, not lobed as inthe Peccary at its summit. 
The outer surface is strongly convex. The most interest- 
ing feature of this tooth, however, is its large basal vacuity 
for a persistent pulp, declaring relationship with the pro- 
genitors of the hippopotamus. The fang retains to its 
lower end the triangular shape, and the width given to it 
by the crown: and its walls are gradually reduced to the 
thinness conditioned by a persistent matrix. On the fore 
outer edge of the tooth the enamel descends within 1°5 mm. 
of the bottom; on the fore inner edge, to the height of 8°5 
mm. above it ; on the hinder and inner surfaces, it is disposed 
as in Dicotyles. The length of the tooth is 36 mm.; the 
breadth of its crown, 12mm. The second example from 
the same side as the preceding shows apparently a sexual 
modification. In proportions, much stouter and shorter, 
its anterior surface is, towards the summit, obscurely sub- 
