138 



ROY L. MOODIE 



dant throughout the Upper Eocene, the whole Oligocene and Miocene, 

 ending their long career in the Pliocene. In distribution the family 

 was exclusively North American and no trace of it has been found in 



any other continent Dr. Leidy, who first discovered and 



named most of the genera, spoke of them as combining the characters 

 of camel, deer and pig, and called them 'ruminating hogs' .... 



The writer has already ('15) figured an imperfect brain cast 

 of one species (Merycoidodon) of this group, and with the pres- 

 ent nasal casts there is associated a splendid brain cast, which 

 will be described at another time, in conjunction with other 

 brain casts of Tertiary mammals. 



64ms frontalis 



Gyrus, lateralis 



Sinus maKtUans superior 



\Zeriroscerebell 



Medulla spinalis 1 



Medulla oblongato 



Ostium maxillar 



Sinus inaxillans 

 inferior 



Ostium accessonum 



Sinus maxillaris inferior 

 [Pars anterior! 



Fig. 3 Lateral view of the casts of the brain and accessory nasal sinuses of 

 Merycochoerus. X §. 



The species represented by the present cast is a member of 

 the genus Merycochoerus. 1 The position of the sinuses (fig. 4) 

 is indicated in an outline of a skull figured by Matthew. The 

 skull was slightly distorted by pressure and the brain and sinuses 

 do not fit in an exact manner; but sufficiently well to show their 

 location. The elongate nature of the maxillary sinus is evident 

 having a most unusual posterior extent. 



Although the sagittal crest is fairly well developed in this 

 species there are no sacculations of the frontal sinus in this 

 animal, such as occurs in the pig (Sisson '14, fig. 180), and the 

 ox (Sisson, fig. 135); although the diploic air-spaces were en- 



1 Matthew, W. D. 1901 Mem. Amer. Museum. Natl. Hist., vol. 1, pt. VII, 

 p. 405. 



