BRAIX OF A FOSSIL UNGULATE. 



879 



case as a kiiife-like ridge which rises as high as 16 mm. above the 

 general surface. As it nears the occiput the crest somewhat 

 thickens and meets the equally highly developed and more massive 

 lambdoid crest a.t right angles. 



The root of the zygomatic process is ver}'' extensive and slightly 

 convex antero-posteriorl}^. Its widely concave form in a trans- 

 verse direction indicates a temporal arcade standing well out from 

 the skull. 



Text-fiff. 150. 



Dorsal view of skull of Anojilot/ieriuni. 

 fr., frontal; par., parietal; sq., squamosal. 



In lateral view (text-fig. 151) the great height of the sagittal 

 and the true form of the lambdoid crests are displayed. This 

 latter strikes off at right angles to the sagittal for about 2 cms., 

 slightly dropping in elevation as it does so, theii falling very 

 sharply downwards, forwards, and slightly inwards, is con- 

 tinued as a much less pronounced ridge to the posterior root 

 of the zygoma. Here it bifurcates, the anterior branch being an 

 extension of the vertical flange of the zygomatic process, while 

 the posterior runs down, and slightly back, on to the huge par- 

 occipital process, on which it dies out. The aperture of the 

 external auditory meatus between the paroccipital and zygomatic 

 processes is remarkable in being formed above by a groove in the 

 squamosal, while the tympanic forms its floor alone, there being- 

 no ordinary bony tube. 



In occijntal vieio (text-fig. 152) the foramen magnum is seen to 

 be nearly circular and the condyles massive. Above, the lamb- 

 doidal crest forms a large shield-shaped area much roughened for 



59* 



