BASIS OF THE SKULL. 129 



between the mastoid process and the condyle of the lower jaw, 

 and extends obliquely forwards and imvarch, having tiie 

 occipital bone behind it, and the glenoid cavity or fossae and 

 the OS sphenoides before it. At the commencement, the 

 surface of the petrous portion is not horizontal, but oblique, 

 sloping into the glenoid cavity with a sharp edge downwards. 

 This edge in some cases is curved so as to surround the basis 

 of the styloid process, which arises in contact with it, and 

 projects downwards, on each side of the vertebne. Between 

 the mastoid and styloid process, is the foramen stylo-mastoi- 

 deum. On the inside of the styloid process, and rather anterior 

 to it, is the foramen lacerum posterius, for the internal jugular 

 vein, the eighth pair of nerves, fcc. This foramen passes 

 obliquely backwards and upwards, and is bounded behind by 

 the jugular process of the os occipitis, which bone seems to 

 contribute most to its formation. Very near to this hole on the 

 inside is the anterior condyloid foramen ; and rather anterior to 

 it is the opening of the carotid canal, which forms a curve in the 

 bone as it passes upwards, inwards, and forwards. 



From the foramen lacerum posterius, the suture between 

 the cuneiform process of the occipital and the petrous portion 

 of the temporal bone, extends to the foramen lacerum anterius 

 of the base of the craniun) ; which is closed by cartilage in 

 the recent subject, but is of an irregular and rather triangular 

 form in the macerated head ; this hole is formed by the 

 occipital, sphenoidal, and petrous bones. The suture or 

 connexion between the petrous bone and the os sphenoides, is 



lary bones. 2. The incisive, or anterior palatine foramen. 3. The palate pro- 

 cess of the palate hone. The large opening near the figure is the posterior 

 palatine foramen. 4. The palate spine ; the curved line upon which the num- 

 ber rests, is the transverse ridge. 5. The vomer dividing the openings of ihr 

 posterior nares. C. The internal pterygoid process. 7. The scaphoid fossa. 8. 

 The external pterygoid plate. The interval between and 8 (left side of the 

 figure), is the pterygoid process. 9. The zygomatic fossa. 10. The basilar 

 process of the occipital bone. II. The foramen magnum. 12. The foramen 

 ovale. 13. The foramen spinale. 14. the glenoid fossa. 15. The meatus audi- 

 torius externus. 10. The foratnen lacerum basis cranii. 17. The carotid fora- 

 men of the left side. IS. The foramen lacerum posterius, or jugular foramen. 

 19. The styloid process. 20. The stylo-mastoid foramen. 21. The mastoid 

 process. 22. One of the condyles of the occipital bone. 23. The posterior 

 condyloid foramen. 



