534 



OJr THE SKULL OF DlNOTIIERltJM GlGANTJfctM. 



in that group of Tetrabeloclonts to wbich Professor Osborn gives 

 the name Rhynchorostrinse, the most extreme case being 

 T^ dinotherioicles. This deflexion of the mandibular symphysis 

 led to the development of the flexible free trunk, just as the 

 shortening of the symphysis did in the main stem, but while in 

 this the vijjper incisors tended to increase in size, in the 

 Dinotheres they disappeared. 



The dimensions of the skull above described (taken on the cast) 

 are : — 



cm. 



Length from occipital condyle to tip of premaxillse. 1 2 1 

 Length from posterior border of palate to tip of 



premaxilla? 84 



Width between outer angles of the squamosals ... 90 

 Width between outer boi'ders of the zygomatic 



processes 74 



Width between the openingis of the ear 68 



Length of glenoid surface from before backwards. 6*3 



Width of glenoid surface from side to side 24 



Width of the occipital condyles 31 



Width of skull just in front of the ant-orbital 



foramen 57 



Width of the anterior end of the premaxilke 31 



Length of molar-premolar series 47 



Length of molar series , 30-2 



