OREODON. 49 
Inches. Lines. 
Length of series of upper true molars : é : : 5 és fae Ils 
Antero-posterior diameter of last upper molar ; . : Z : : 93 
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 fecbly 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specimen 10, and externally it is obsolete.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-orbitar foramina. . j ; ‘ : ie Tt 
Breadth of face above first premolar : E 1 7k 
Distance from infra-orbitar foramina to frontal cali processes. 3 al 2 
Breadth of hard palate posteriorly ; : : ¢ ; : : Sorel 5 
Breadth of hard palate anteriorly t il 4 
Extent of hiatus posterior to the upper canine 2% 
Length of series of upper molars 8 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. 
Breadth of face at infra-orbitar foramina ; : 3 j : 5 steel 53 
Breadth of face above first premolar. : ; : ; ot tag 4} 
Distance from infra-orbitar foramina to frontal Spence processes. , etl 4 
Breadth of ossa nasi at the ends of the latter processes . é : : : 11 
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- 
