1. premaxilla. 2. nasal. 3. frontal. 4. parietal. 5. supra-occipital. 6. epi-otic. 7. pro-otic. immediately in front of the figure 7 is the prominent foramen for the trigeminal nerve. 8. opisthotic. 9. basi-occipital. 10. quadrate. 11. pterygoid. 12. basisphenoid. 13. alisphenoid. 14. prefrontal. 15. vomer. 16. maxilla. 17. palatine. 18. dentary. 19. splenial. 20. angular. 21. supra-angular. 22. articular. 23. coronoid. 24. exoccipital. 25. squamosal. 26. jugal. 27. external mandibular foramen. 28. internal mandibular foramen. VIII. internal auditory meatus. XII. hypoglossal foramen.] The _maxillae_ (figs. 43, A, 2 and 44, 2) are a pair of very large bones and bear the remaining teeth of the upper jaw, set in sockets along their alveolar borders. On the dorsal side each maxillae is continuous with the premaxillae, nasal, lachrymal, and jugal, while ventrally it meets its fellow in a long straight suture and forms the greater part of the long bony palate. The maxillae are separated in the middle line posteriorly by processes from the palatines, while further back they meet the transpalatines. The internal or nasal surface, like that of the premaxillae, is excavated by a deep longitudinal groove, the =narial passage=. In a ventral view of the skull a number of small openings (fig. 43, A, 21) are seen close to the alveolar border, these are the openings of small vascular canals which lead into the =alveolar sinus=, a passage traversing the maxillae, and transmitting the superior maxillary branch of the trigeminal nerve and certain blood-vessels. This alveolar sinus opens posteriorly by the more external of the two large holes in the maxillae, which lie close to the anterior edge of the posterior palatine vacuity, to be described immediately. The more internal of these holes, on the other hand, leads into a cavity lodging the nasal sac. Behind the maxillae the completeness of the palate is broken up by the large oval =posterior palatine vacuities= (fig. 43, A, 7); these are separated from one another in the middle line by the palatines, and are bounded elsewhere by the maxillae, transpalatines, and pterygoids. The _palatines_ (fig. 43, A, 3) are long and rather narrow bones interposed between the maxillae in front and pterygoids behind. They meet one another in a long suture and form much of the posterior part of the palate, while the whole length of their dorsal surface contributes to the floor of the narial passage. The dorsal surface of each bone is also drawn out on its outer side into a prominent ridge which forms much of the side and roof of the narial passage, being in contact with the vomer and pterygoid, and at one point by means of a short ascending process with the descending process of the prefrontal.