88 ON THE OSTEOLOGY OF THE CHIMPANZEES AND ORANGS. 
9. Presphenoidal sinus. 
9. Cranial surface of presphenoid. 
u. Frontal. 
u1'. Superorbital ridge. 
16. Petrosal. 
e. Eustachian process. 
28. Tympanic. 
au. External auditory foramen or meatus. 
m. Internal auditory foramen. 
v. Vaginal process. 
38. Stylohyal fossa. 
c. Carotid canal. 
pg. Post-glenoid process. 
g. Entoglenoid process. 
s. Styliform process. 
st. Styloid or spinous foramen. 
tr. Foramen ovale. 
15. Nasal. 
rh. Rhinencephalic fossa. 
20. Palatal. 
21. Maxillary. 
22. Premaxillary. 
22'. Facial part of premaxillary joining the nasal. 
22". Suture between this part and the rest of the premaxillary. 
25. Pterygoid fossa. 
26. Malar. 
26'. Zygomatic process of malar. 
27. Squamosal. 
27'. Zygomatic process of squamosal. 
73. Lacrymal. 
C....C. The line intersecting the facial line according to the method of Cuvier. 
B----B. The line intersecting the facial line to form the palato-facial angle. 
O—O. 'The line intersecting the facial line to form the basifacial angle, as proposed 
by the author (p. 92). 
D.-.-.-D. The line crossing the plane of the foramen magnum and intersecting the 
basal line, as proposed by Daubenton. 
