94 TERTIAEY VERTEBEATA OF THE EAT^M. 



thin alveolar border. About 2'5 centimetres behind the large tooth are two small 

 alveoli for a double-rooted incisor {i. 2), and behind this again the remains of another 

 double-rooted tooth, the third incisor (i. 3). The presence of these peculiar double- 

 rooted incisor-teeth seems to show that the same causes, whatever they may be, which 

 gave rise to a double-rooted premolariform canine also affect the two posterior incisors, 

 so that all the teeth behind the first incisor practically form a series of cheek-teeth. 



Comparison of this premaxilla and its contained tusk with the premaxilla and 

 incisor of a recent Hyracoid show that, as in Saghatherium magnum, the two are 

 closely similar in most respects. The presence of the two posterior incisors is just 

 what might be expected in this early form, the remarkable thing being not the 

 difference between the Eocene forms and recent types but their great resemblance, 

 which shows that, so far as the front of the skull is concerned, the older forms were 

 almost as peculiar as the modern ones. 



Among the specimens collected by Mr. Beadnell in 1903 is the cranial portion of 

 a skull (text-fig. 39) which, from its resemblance to the corresponding part of the skull 

 of Saghatherium antiguum, may reasonably be referred to a Hyracoid, and from its 

 size most probably belongs to the present species. 



The occipital condyles (cond.) are large and sharply truncated at their upper border. 

 The foramen magnum [f.m.) is roughly quadrate in outline. Above and external to 

 the condyles there is on either side a deep depression separating them from the 

 strongly developed paroccipital processes {p-p.) which project below their level. The 

 occipital surface widens out a little above the condyles and its upper border forms 

 the middle portion of a high prominent lambdoidal crest, which is continued 

 downwards and outwards on to the squamosal and is continuous with the upper edge 

 of thie zygomatic process of that bone. Just below the lambdoidal crest the occipital 

 surface bears in the middle line a roughened ridge flanked by two smaller lateral 

 ones ; this portion of the surface slopes somewhat backwards. Between the upper 

 edge of the paroccipital process and the squamosal there is a slit-like foramen lying 

 immediately beneath the lambdoidal crest; laterally and external to the slit the 

 anterior face of the paroccipital region of the exoccipital is closely apposed to the 

 posterior face of a nearly vertical ridge of the squamosal, the two limiting a 

 well-marked groove. Between the just-mentioned vertical ridge and the upper 

 border of the zygomatic process is a triangular area, at the bottom of which the 

 auditory opening must have been ; the anterior border of this depression is formed by 

 a prominent postglenoid process {fgl-)- 



There is a strong sagittal crest (s.c.) running forwards from the lambdoidal ridge till 

 it bifurcates. The temporal ridges (p.orb.) thus formed run out on to the posterior 

 borders of the supraorbital processes. The brain-case is strongly rounded and slightly 

 contracted a little behind the orbits. The frontal region (fr.) is very broad and flat, and 

 closely resembles the same portion of the skull of Saghatherium and Hyrax (Procavia). 



