366 ROY L. MOODIE 
and 32 mm. across its widest part. It displaces 20 cc. of water. 
The cerebral pattern is so similar to that of Oreodon, as figured 
by Black (’20), that nothing need be said concerning it, save to 
point out the absence of all complexities. This, however, may 
be due to the cast’s being that of a young animal in which the 
complexities had not yet impressed themselves on the inner 
table of the skull, or it may be a specific character. 
The cerebellum shows the same prominence as indicated by 
Black in the specimens he studied, but otherwise the cast is too 
eroded to add to our knowledge of this important phase of 
endocranial anatomy. 
Another larger cast of Oreodon gracilis and apparently of a 
more mature individual has recently been loaned me by Mr. H. T. 
Martin. This cast, likewise shows no complexities in the sulci 
of the cerebrum. The cast is broken at the tentorial line, but 
anteriorly there is a magnificent exhibition of the paranasal 
sinuses, especially interesting in showing the relation of the 
olfactory bulbs to the frontal sinuses (fig. 21). The length of 
the cerebrum measured from the tip of the olfactory lobe is 
48 mm., the width is 35 mm. The outer ends of the olfactory 
bulbs are flattened obliquely against the ala ossis frontalis, 
thus causing the bulbs to end in median sharp points. The 
upper surfaces of the bulbs are smooth and rounded with a cleft 
4 mm. wide and 6 mm. long separating the anterior parts. They 
join the cerebrum by a common base. ‘This particular region was 
badly broken in the specimen of Merycochoerus. 
The casts of the paranasal sinuses, while not so complete as 
those previously figured (Moodie, 716), are of especial importance 
in showing the relations of the sinus frontalis and the various 
sacculations of the sinus maxillaris superior to the olfactory 
bulb. The casts of the frontal sinuses are mostly broken, but 
the portions remaining indicate a multiple nature for this sinus 
in Oreodon gracilis, as it is found to be in Merycochoerus. ‘Three 
small sacculations of the sinus maxillaris superior come into 
intimate relation with the olfactory bulb, being separated from 
actual contact by the paper-like alae of the frontal bone. The 
smooth surfaces of all the casts of the sinus maxillaris superior, 
