BY C. W. DE VIS. 
91 
the hinder with a narrow groove near the inner angle. In the 
young tooth the impression and groove are the terminal limits of 
an oblique superficial cleft separating the extero-posterior angle 
from the rest of the tooth, which cleft is traversed and beset by 
enamel folds and processes; in teeth reduced to a horizontal 
surface these processes appear in section as a group of sinuous 
folds occupying most of the centre of the hinder portion of the 
tooth, and surrounded on the outer side by a long crescentic band 
of dentine. Diameters 12-7 x 11.1. 
Molars. — (PL xv. fig. 9). The edge of the anterior talon is on 
the inner side double. From the inner side of both links low 
vertical folds descend to the valleys. Two or three strong vertical 
folds project from each face of the inner half of the fore lobe, a 
single fold from the anterior face of the hind lobe; a strong 
tapering fold rises upon the centre of the posterior surface of that 
lobe. The links are lofty and sharp. 
Maxillary. — P. 4 (PI. xv. fig. 6). Extracted from its crypt in 
a forward stage of growth is irregular oblong, with convex angles, 
diameters 11*9 x 9*0. Outer side nearly straight, inner with a 
deep impression at its anterior two-fifths. Fore end sloping, with 
oblique folds. Intero-posterior region of crown much dilated, its 
surface depressed, concave; its edges at each end rising upon the 
side of the main lobe, and its posterior surface separated from 
that of the lobe by a wide cleft which does not descend to the 
base. The concavity of the ledge is traversed longitudinally by 
a single sinuous ridge-like fold. On the hinder half of the outer 
side of the crown tapering ridges ascend to the crest. 
P.'" (PL xv. fig. 5) much mutilated and worn down to a field of 
dentine surrounding a patch of enamel, on the surface of which 
sinuous enamel folds still appear in section. The inner side of 
the crown is impressed at its anterior fourth. Diameters 8*5 x 
8-5. 
Rise and fall of teeth. 
On this point the limited number of specimens afford sparse 
information. In the upper jaw the penultimate molar appears to 
