ENDOCRANIAL CASTS OF THE GIRAFFIDAE 339 
The prominent asymmetrical boss formed in the mesial plane 
by the median lobe of the interfloccular mass is distinctly out- 
lined and is separated. by a well marked furrow from the less 
prominent lateral areas of this mass. Rostrally the median 
protuberance ends abruptly in a depression occupied in the 
recent state by the junction of the falx cerebri and the tentorium 
cerebelli. The lateral cerebellar swellings apparently correspond 
to those portions described by Elliot Smith (10) as Area B of the 
interfloccular mass (=Crus I of Bolk, 4). These lateral areas 
are placed dorso-caudal to the floccular region, from which 
they are only separated by an indistinct groove. On the whole 
it may be said that, in its general morphology, the cerebellar 
portion of this cast recalls the condition obtaining among the 
Gervidae. 
Unlike the condition found in the giraffe, the olfactory bulbs 
in okapi are pedunculated and project a considerable distance 
beyond the frontal poles of the cerebrum. The fossae lodging 
the olfactory tracts are well developed. 
It should be noted here that the asymmetry of the portion of 
the cast representing the olfactory bulbs and tracts and optic 
nerves is due to the defective restoration of these parts after 
they had been damaged on the left side. 
As the remaining structures represented in the basal portion 
of the cast differ in no important detail in their general relations 
from those already described in the giraffe, further description 
of this region may be dispensed with. 
Cerebral hemispheres. The arrangement of the sulci appear- 
ing upon the dorso-lateral surface of this cast gives evidence 
of a close relationship between the okapi and the giraffe. The 
arcuate constellation and the arrangement of the lateral group 
of sulci in the okapi are essentially similar in their relations to 
the corresponding furrows already noted in the giraffe. There 
are, however, not a few significant differences, to which attention 
will be drawn in the following description. 
Dorsally (figs. 5 and 21) the relations of the lateral sulci to 
the coronal and suprasylvian are evident and present no unusual 
feature. However, the changed relations of the coronal, ansate 
