90 TEETIAEY VEETEBEATA OF THE FATtrM. 



be regarded as consisting of two elements {a.e. and p.e.) imperfectly divided ; the 

 postero-internal angle of the tooth forms a greatly worn shelf-like projection. In this 

 tooth, as in the premolars, the enamel of the ectoloph is very thick, so that in wear it 

 forms a prominent cutting-edge. The suture between the maxilla and premaxilla 

 crosses the outer edge of the alveolar border immediately in front of the canine and 

 runs on to the face — at first upwards, then backwards. On the inner side of the 

 alveolar border the suture runs forwards, the maxUla apparently sending a process 

 forwards beneath the premaxilla, somewhat like that described in Mosritherium. As in 

 the latter genus, this peculiarity is probably correlated with the presence of enlarged 

 tusk-like incisors. Immediately in front of the suture is the alveolus of a single- 

 rooted third incisor, the crown of which must have been in contact vsdth that of the 

 canine, so that it actually formed one of the series of cheek-teeth, which thus consists 

 of three molars, four premolars, a canine, and the last incisor. About 4 mm. in front 

 of this is a smaller alveolus for the second incisor. Anterior to this the alveolar 

 border becomes concave and widens out to the socket of the great trihedral first 

 incisor. Of this tooth, unfortunately, only the base is preserved : it is triangular in 

 section and probably grew from a persistent pulp. The convexity on the side of the 

 face caused by its alveolus can be traced back to the level of the first premolar. The 

 antero-external and antero-internal faces are covered with enamel, but this is absent 

 from the posterior face. In short, it may fairly be said that, except for the presence 

 of the two small posterior incisors, the premaxilla and its tusk-like tooth are 

 practically identical in form with those of the modern Hyrax, and there is no clue 

 to the manner in which this curious modification arose. 



The lower teeth are similair to those of ;S'. antiguum, except that the meta- and 

 ento-stylids are more strongly developed (see PI. VI. figs. 4, 4 a). 



M. 8398. Right maxilla and premaxilla with molars, premolars, canine, and the base of the first 

 incisor : i. 2 and i. 3 are represented only by their alveoli. The type specimen 

 described in Geol. Mag. [5] vol. i. p. 214; figured in Greol. Mag. [4] vol. x. p. 340, 

 fig. 2, as S. antiquum ; also on PI. VI. figs. 3, 3 A. The dimensions (in centimetres) 

 o£ this specimen are : — 



Length of tooth-series (molars, premolars, canine) . . . . 7'8 



„ premolar series 3'2 



„ molar series 3"9 



„ m.3 1-7 



m.2 1-5 



m. 1 1-0 



„ pm. 4 1-0 



„ pm.S -9 



„ pm.2 -8 



„ pm.l "S 



Total length of the specimen is 10*1 cm. 



