PLATE XIII. 



Vis. 



1. Paheomastodon C?) headnelli, Andrews ; anterior portion of young skull, upper 

 and (1 a) side views : three-fourths nat. size; also (1 b) crown view of left 

 upper teeth : nat. size. Fluvio-marine beds (Upper Eocene). [C. 8116.] 



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138 



ao.f., antorbital foramen. 

 /(•., frontal. 

 i., incisor. 

 ja., jugal. 

 lac, lachrymal. 

 mes.ff., mesethmoid groove. 

 mm. 2-4, milk-molars. 



mj;., maxilla. 



na., nasal. 

 nar., external nares. 



orb., orbit. 

 pal., palate. 

 •pnix., premaxilla. 

 -y9-^ zygomatic process of maxilla. 



