1909. | ANATOMY OF CERTAIN UNGULATA, 163 
text-book*, The most recent account known to me is that of 
Dr. Elliot Smith in the Catalogue of the Physiological Series in 
the Museum of the Royal College of Surgeons f. 
{ have examined altogether fourteen brains of Tyrax capensis, 
which permits me to contribute something to what is known of 
the variations of the sulci in this Subungulate. None of these 
brains, 1 should add, was among those studied by Dr. Elliot 
Smith. This anatomist has studied seven brains and finds “ that, 
the features of the brain vary greatly in different specimens.” 
In addition to the brains of Myrax capensis, 1 have examined 
one brain of /, dorsalis. J shall now proceed to review such 
variations as are exhibited in the fourteen brains of JI. capensis, 
commencing with the dorsal surface, 
The splenial sulcus is figured by Elliot Smith as invisible pos- 
teriorly upon the dorsal surface; its position for the last 5 mm. 
or so of its length is mesial and lateral, and it is therefore not 
to be seen when the brain is regarded from the dorsal surface. 
This was also the case with four of the brains examined by 
myself. In the others the sulcus could be seen dorsally for its 
entire length. This was also very markedly the case with the 
one brain of /T. dorsalis. 
As a rule, the splenial sulcus is quite independent of the 
coronary and lateral sulci. The blood-vessel running along it, 
however, is formed by two branches, one behind the other, to the 
vessel running along the coronary sulcus. ‘These naturally 
dahil indent the surface of the brain. But in two specimens 
only out of the entire series, and in them only on the right side, 
was there a distinct furrow joining the splenial to the posterior 
end of the coronary. his furrow represe nts an extension of the 
small notch figured by Elliot Smith? as lying between the 
coronary and lateral sulci. The aicngianel completion of this 
fissure is of course suggestive of other Ungulates §. he coronary 
fissure does not always stop short of the transverse fissure or notch 
in the middle of the length of the brain which has just been 
referred to. This was, however, the case with six brains. In the 
others the coronary fissure was connected by the transverse fissure 
with the suprasylvian. 
In the single brain of Myrax dorsalis there was no connection 
between the coronary and the suprasylvian. 
The lateral fissure showed no variations except very slight ones 
of length. 
The lateral view of the brain is figured by Elliot Smith in two 
examples, which differ very considerably. J have also found a 
certain number of variations in the sulci of this region of the 
brain, which are the following :— 
In eight examples I found the suprasylvian fissure to be very 
* © Anatomy of Vertebrates,’ vol. iil. fig. 96. 
+ 2nd ed. vol. ii. p. 297. Dr. Elliot Smith quotes also a memoir by Turner 
(J. Anat. Phys. xxv. 1891) and Krueg’s well-known paper; see also Elliot Smith, 
Trans. Linn. Soc., Zool. (2) viii. p. 400. 
{ Loe. cit. p. 297, fig. 168. § See below, p. 173, and text-fig, 11. 
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