PLATE X. 



Fig. Page 



1. Mosrithermm lyonsi, Andrews; left ramus of mandible, with the molars and 

 premolars, upper and (1 a) outer views ; the posterior portion is restored 

 in outline from other specimens : one-half nat. size. Qasr-el-Saaha beds 

 (Middle Eocene). [Type specimen, C. 10000. ] 108 



2i Ditto ; right upper cheek-teeth, crown view : one-half nat. size. Same 



horizon. [C. lOOOl.J 106 



3. Ditto ; anterior portion of skull, side view : one-half nat. size. Same 



horizon. [C. 10002.] 99 



4. Ditto ; posterior portion of the same skull, upper and (4 a) posterior views : 



one-half nat. size. Same horizon. [C. 10002.] 99 



5. Ditto; crown of last upper molar : one-half nat. size. Same horizon. 



[M. 8902.] 108 



a.o.f., antorbital foramen. 



C.J canine. 

 cond., condyle of mandible. 



cor., coronoid process. 

 e.a.m., external auditory meatus. 



exo,, exoccipital. 

 i. 1-3, incisors or alveoli of incisors. 

 TO. 1-3, molars. 



TO./., mental foramen. 

 TOa-., maxilla. 



na., nasals. 

 nar., external nares. 

 orb., orbit. 

 pa., parietal. 

 pm. 2-4, premolars. 

 pmx., premaxilla. 

 poc, paroecipital process. 

 soc, supraoccipital. 

 sq., squamosal. 



