248 COPE. [Vov. III. 
molar, which thus closes the space between its crown and that 
of the adjacent superior molar ; and by a corresponding change 
in the inferior molar. In this tooth the anterior interior cusp 
has disappeared, and the two cusps of the heel have become 
elevated, so as to be on a level with the remaining anterior 
Figure 71.— Transverse vertical sections of superior molar teeth, showing transi-— 
tion from bunodont (7) type to lophodonts (2, 7). Fig. 1, Sas erymanthius. Fig. 
2, Ovis amatheus. Fig. 3, Bos taurus. From Ryder, after Gaudry. Letters: @. den- 
tine; ¢. enamel; c, cementum. 
Figure 72. — Transverse vertical sections of molars of Proboscidia, showing same 
transition as in last figure; lettering the same. Fig. 1, Dinotherium giganteum ; 
Fig. 2, Mastodon americanus; Fig. 3, Elephas ganesa; Fig. 4, E. planifrons ; Fig. 
5, Z. hysudricus ; Fig. 6, 2. indicus. 
