ENDOCRANIAL CASTS OF THE GIRAFFIDAE 341 
In the Cervidae and in other forms where the descending ramus 
of the suprasylvian is usually small, the oblique sulcus is large, 
and passes forward into the region which is occupied in the 
giraffe by the large descending ramus suprasylvii (figs. 10 and 12). 
Also in Cervidae, this oblique sulcus often cuts the posterior 
rhinal fissure, either independently or by joining the ramus 
posterior ectosylvii. . 
I have already (3) mentioned the possibility of the oblique 
sulcus in Cervidae (fissura postica of Krueg, fissura suprasylvia 
posterior of Flatau and Jacobson) being the homologue of the 
prolonged descending ramus of the suprasylvian in okapi. I 
am, however, inclined to modify this view somewhat on further 
study of the relations of the sulci in this region. 
In the giraffe (fig. 3) the descending ramus of the suprasylvian, 
the oblique and the ramus posterior ectosylvii, are each to be 
distinguished as separate sulci. In the okapi, however (fig. 6), 
the suleus termed ramus descendens suprasylvii is much more 
caudally placed and cuts the rhinal fissure (see also Samotherium, 
fig. 9). Thus, the arrangement of this constellation in the 
okapi is such as to suggest at least the possibility of its repre- 
senting, not the oblique sulcus only, but rather a complex of 
three sulci, viz., the ramus descendens suprasylvu, the oblique 
and the caudal end of the ramus posterior ectosylvii. 
The possibility of this is increased when it is remembered that 
such combinations of sulgi are not rare, and that in this same 
cast other examples of such a phenomenon have been noted 
(corono-ansate-suprasylvian and also suprasylvian-diagonal). 
The irregular sulci marking the caudo-lateral surface of the 
cast are thus to be considered as representing the triradiata 
posterior of Kappers. 
(c) Samotherium (figures 7 to 9 and 23 to 25) 
This primitive ruminant, resembling the modern okapi, was 
discovered in upper Miocene deposits in the island of Samos 
(Forsyth Major, 15, 16). Like the okapi, horns were present 
only in the male and were situated upon the frontal bones. 
