680 - THE BEIDOEE FAUNA. 



above the latter, but does not contract below until the first premolar is 

 reached. The zygomatic arch is not convex along- its middle, and incloses 

 a narrow fossa. The superciliary border is prominent, and nearly straight, 

 and is bounded by a notch behind. The squamoso-occipital ridge is well 

 marked. The posttympanic process is shorter than the paroccipital, and is 

 separated from it by an open shallow groove, which is probably bottomed 

 by the mastoid bone. The paroccipital process is much narrowed below 

 and is turned a little outwards. There are two closely adjacent tubercles 

 on the anterior border of the orbit, probably on the lachrymal bone. 



Foramina. — Only a few of these are well preserved; among the lost is 

 the/ infraorhitale. There are two postparietal foramina on one side, and 

 one on the other, above the point of origin of the zygomatic process of the 

 squamosal bone; and one in the usual posterior position. The postsqua- 

 mosal has the same anterior position as the anterior postparietals, being 

 immediately below them; I cannot discover whether there is a posterior 

 one or not, owing to injuries to the specimen. There is a))parently a fissure- 

 like one on the parieto-squamosal suture posteriorly. The mastoid is quite 

 large, expanding downwards and outwards; it is not so large as in a tapir, 

 but much exceeds that in Hyrachym eximkis. The meatus auditorius externus 

 is large, and occupies only the posterior part of the space between the 

 postglenoid and posttympanic processes. It is inclosed anteriorly and 

 below by the border of a wide element which may be tympanic. It in- 

 closes the petrous bone below in a bulla; as, however, the inner portion of 

 the best preserved one is broken away, I cannot speak of its relations to 

 the basioccipital bone. The foramen lacerum x>osterius is reduced to a jugular 

 and perhaps another connected foramen by the close apposition of the pe- 

 trous bone to the basioccipital for a considerable distance. The region of 

 the/ I. medkis is injured. Postei'ior to the/ I. poster kis is a foramen oppo- 

 site the base of the paroccipital process, anterior to the usual position of 

 the / condyloideum. 



Mandible. — The angle of the lower jaw is produced posteriorly, as in 

 some species' of Hijrachyus : cfr., fig. 1, pi. LYI a, and fig. 2, pi. LIII. 

 The coronoid process is long and is curved backwards to above the jDOSte- 

 ri(n- border of the condyle. There is no tuberosity behind the condyle. 



