22 
ERIK A : SON STENSIO 
cone one can observe close to it a small lateral cone and it is probable that a similar 
one also existed on the other side, as everything seems to indicate that the tooth was 
developed symmetrically. The basal margin of the crown has three small sinus appearing 
basally on the preserved half. The sculpture is mainly restricted to the principal cone 
and consists of a few fine vertical striae. — The root seems to have been comparatively 
low and has probably been bent in about the same way as the crown. 
The other of the anterior teeth (PI. 3 , figs. 2, 3 ) is considerably better preserved 
than the former and its two sides are known. It is somewhat more than xi mm in length 
and its greatest height is 5 mm. Both the root and the crown are bent in the same 
way as in the preceding tooth, but somewhat more strongly. The crown has a broad 
blunt principal cone and a very small blunt lateral cone ■ on each side of this. The 
basal margin of the crown is without such sinus as are found in the above described 
tooth. A marked longitudinal crista extends over the principal cone from one end of 
the crown to the other. From this crista there issued on both sides a number of very 
short striae. Apart from these the sculpture consists of fine striae, situated sparsely, 
occurring both on the principal cone and the rest of the crown. The striae are fairly 
parallel to one another, vary in length, and have a transversal (vertical) course. Those 
on the basal part of the crown are best developed. 
As far as one can judge, ,the root seems to be somewhat narrower than the crown. 
Its two ends are truncated and comparatively high. The basal edge is concave, the 
dorsal one correspondingly convex. 
There are several teeth preserved which seem to form transitional types between 
the two just described and those of the middle transverse rows. 
One tooth of this category is about 1 x mm long. Its crown is strongly bent in the 
same plane as in the two teeth described above and is higher at the middle than towards 
the ends. Avery slight bluntly rounded principal cone is present. Lateral cones on the 
other hand are quite absent. From the middle the crown grows continuously narrower 
towards the ends, which are fairly pointed. The sculpture agrees closely with that we 
have already seen on the two anterior teeth, but it appears to be somewhat more power¬ 
ful, especially in the case of the striae that issue from the longitudinal crista. 
A somewhat larger tooth measuring about i 3 to 14 mm in length and with a 
maximum height of almost 5 mm (PI. 3 , fig. 4) shows a great resemblance in several 
respects to the last-described tooth. It differs from this by an asymmetrical develop¬ 
ment — its highest part is situated somewhat towards one end — and by the absence 
of a rounded angle. Another tooth (PI. 3 , fig. 5) of about the same size as the former 
is symmetrically developed, and has, as will be seen, a fairly wide crown with rather 
strong sculpture, which is, however, incompletely preserved. The sculpture consists on 
the middle part of one side — whether it is the medial or the lateral side cannot be 
decided — of transversal striae, extending from the basal margin of the crown up to 
and joining the well developed longitudinal crista. On the remaining part of the same side 
and probably the whole of the other there seem to be short stumps of striae issuing 
from the longitudinal crista, while other similar stumps were probably present close to 
the basal margin of the crown. The striae consequently appear to have been disconti¬ 
nuous in their middle. 
