498 
PROFESSOR OWEN ON THE DENTITION OF PHACOCHCERUS. 
Fig. 6. View of tbe grinding surface of the upper molar series of a full-grown but 
young Phacochosrus jEliani. 
Fig. 7- A similar view of the molar series of the lower jaw of the same specimen. 
Fig. 8. Side view and view of the grinding surface of the molar series of a similarly 
aged Phacochmrus Pallasii. 
Fig. 9. View of the grinding surface of the upper molar series of an older Phacochcerus 
Mliani. 
Fig. 10. Similar view of the lower molar series of the same animal. 
Fig. 11. View of the grinding surface of the upper molar series of an older Phaco- 
chwrus Pallasii. 
Fig. 12. Similar view of the upper molar series of a still older Phacochcerus Pliant. 
(The symbols are explained in the text, especially at p. 491. 
