FOSSIL HYRACOIDS FROM THE FAYUM. 849 



C. 8822-3 ; type-specimen (text-fig. 6) ; large fi*agmentof right 

 mandibular lamus, bearing P — M, in situ, and large fragment of 

 left mandibular ramus, including a greater part of symphysis, 

 bearing I „ „ and P, — M, in situ : it is almost certain that these 



° 1 & 2 3 2 ' 



two rami belong to one and the same mandible. 



The symphysis of this mandible is quite difierent from that of 

 the other genera of the Fayum hyracoids : it is I'ather short and 

 very deep, with the anterior lower side very steep ; it' i'ather 

 resembles the mandibular symphysis of a tapir. ISToiie of the lower 

 incisors is tusk-like. Both I, . ^ ^"-'^ alike spatulate, with flat, 

 wide, and thin ci'owns ; their roots are clavate, with constricted 

 proximal parts. Unfortunately, the part of the dental arch cor- 

 responding to I and is broken away in this specimen ; I.^ and 



C must be very reduced, if they were present at all, as can be 

 judged from the very short distance from I,^ to premolars. The 



mandible measures as follows (in mm.) ; — 



Length of symphysis 50 



Depth of the same 37 



Length from tip of symphysis to posterior 



endofP 86 



4 



Depth of ramus at anterior side of P ... 42 

 Ditto at anterior side of M, 53 



All the cheek-teeth are moderately to strongly worn. The 

 entostylid is not well differentiated from the entoconid. All the 

 cheek-teeth are short and wide. The M ^ have a tuber-cle, as a 



part of the posterior basal cingulum, just behind the posterior 

 transverse ridge. 



The teeth of this specimen measure as follows (in mm.) : — 



Eight. Left. 



1-3 



