98 TEETIAET VERTEBEATA OF THE EATtTM. 



The mandibular ramus is massive and does not deepen so rapidly from before 

 backwards as in the other members of the group. The symphysis is short and 

 extends to the level of the posterior lobe of pm. 2. Its ventral surface is marked 

 by a slight prominence, behind which, and forming the ventral border of the mandible 

 for a short distance, is a strong ridge for the attachment of a powerful muscle 

 C? the mandibular) : the same arrangement is very well marked in Hyrax (Procavia). 

 The ascending ramus is broad ; its inner border is formed by a ridge continuous with 

 the alveolar border, while the outer rises on the outer face of the ramus beneath m. 3. 

 The inner border, about 3 cm. above the talon of m. 3, turns sharply outwards and 

 joins the outer border to form the thin anterior edge of the coronoid process : exactly 

 the same arrangement may be seen in the mandible of Hyrax {Procavia). At 

 the bottom of the fossa thus formed behind the last molar, a foramen opens into a 

 passage, the other aperture of which is on the inner face of the posterior portion 

 of the jaw. 



C. 8818. Left maxilla with molars and premolars. Type specimen described in the Geol. Mag. 

 [5] vol. i. (1904) p. 213. Figured on PI. YII. fig. 1. The dimensions (in centi- 

 metres) of the specimen are : length of m. 3, 2-9 ; m. 2, 2'6 ; m. 1, 2'1 ; pm. 4, 1"7 ; 

 pm. 3, 1'5 ; pm. 2, 1*4 ; pm. 1, 1*5. The total length of the molar-premolar series is 

 13j that of the molar series alone 75. 



M. 8870. Plaster cast of the above specimen. 



C. 8882-3. Portions of a mandible including the greater part of the right ramus with pm. 2-4 and 

 m. 1-3, and the anterior portion of the left ramus with part of the symphysis 

 containing pm. 3-4, m. 1-2, and in front two incisors, probably i. 1 and i. 2. 

 Figured on PL VII. figs. 2, 3. The dimensions (in centimetres) of the teeth are : — 



Length. Width. 



TO. 3 3-3 2 



m.2 2-3 1-8 



m.l 1-9 1-6 



pm.4 1-8 1-6 



jom.3 1'6 1-4 



pm.2 1-7 M 



Length of series from^m. 2-ot. 3 inclusive, 12-7 cm. The widths 

 of the crowns of the incisors are : i. 1, 1'4 cm. ; t. 2, 1*6 cm. 



M. 8871. Plaster casts of the above specimens. 



M. 9220. Left ramus of mandible with m. 2-3, pm. 3, and part of pm. 4. 



