Inches. 



Lines. 



1 



lU 





H 



OREODON. 49 



Length of series of upper true molars ...... 



Antero-posterior diameter of last upper molar ..... 



11. The facial portion of a skull, apparently of a male, containing all the 

 molars except the crown of the first premolar. In section, it presents the same 

 squareness of character as in specimen 10, and also has the same flatness above and 

 uniformity of breadth anteriorly. The ossa nasi have been slightly shorter than 

 those in specimen 10, and less rounded posteriorly. 



The specimen is remarkable in comparison with that last indicated, because the 

 true molars are a little smaller and the premolars a little larger ; but this increase 

 of the latter is in breadth, and not antero-posteriorly, so that it produces no effect 

 upon the length of the series. 



The basal ridge of the molars is more feebly developed internally than in 

 specimen 10, and externally it is obsolete. 



The hard palate is slightly more arched, and has a little greater breadth than in 

 specimen 10. 



From Capt. Van Vliet's collection. 



MEASUREMENTS. 



Inches. Lines. 



Breadth of face at infra-orb itar foramina . . . . . . .1 7^ 



Breadth of face above first premolar 1 7 J 



Distance from infra-orbitar foramina to frontal angular processes ... 1 2 



Breadth of hard palate posteriorly ........ 1 5 



Breadth of hard palate anteriorly ........ 1 4 



Extent of hiatus posterior to the upper canine ...... 2 J 



Length of series of upper molars . . . . . ' . . .3 5 



Length of series of upper true molars 1 9 



Antero-posterior diameter of last upper molar 9 



12. A fragment of the face and forehead. The former in transverse section is 

 nearly square, but is rather more arched above than in specimen 10, and is narrower 

 and less deep than usual. 



From Dr. Owen's collection. 



MEASUREMENTS. 



Inches. 



Lines. 



1 



5^ 



1 



4i 



1 



i 





11 



Breadth of face at infra-orbitar foramina . ... 



Breadth of face above first premolar ....... 



Distance from infra-orbitar foramina to frontal angular processes 

 Breadth of ossa nasi at the ends of the latter processes .... 



13. A portion of the face and forehead of an individual just arriving at adult 

 age. Though very imperfect, the specimen is an instructive one, as it exhibits the 

 order of succession of the permanent to the temporary molar teeth. 



Upon the right side, the last molar is preserved and fully protruded, and has 

 the enamel summits of its anterior lobes slightly worn. The second true molar 

 has the dentine exposed upon the summits of the lobes ; most so upon that antero- 



