[Illustration: FIG. 21. LATERAL VIEW OF THE SKULL OF AN ALLIGATOR (_Caiman latirostris_). ×¹⁄₃. (Brit. Mus.) (After Reynolds.) 1. premaxilla. 2. maxilla. 3. lachrymal. 4. prefrontal. 5. jugal. 6. postfrontal. 7. squamosal. 8. quadrate. 9. palatine. 10. pterygoid. 11. transpalatine. 12. quadratojugal. 13. exoccipital. 14. basi-occipital. 15. foramen by which carotid artery enters skull. 16. external auditory meatus. 17. frontal. 18. supra-angular. 19. articular. 20. dentary. 21. coronoid. 22. angular. III, VI, opening for exit of oculomotor and abducens nerves. V, foramen ovale. X, pneumogastric foramen. XII, hypoglossal foramen.] _The Posterior Aspect_ (Fig. 22). Most of the bones seen in this view have already been described. The _pterygoids_ (10) form the two prominent, ventro-lateral projections, while dorsal to these is the large process formed by the quadrate (8) and quadratojugal (12). The dorsal margin is formed by the edges of the parietal (23) and the squamosals (7). Immediately below the parietal is the supraoccipital (26); it is a small, triangular bone, articulating above with the parietal and squamosals, below with the exoccipitals, and anteriorly with the epiotic. It takes no part in the formation of the foramen magnum. The _exoccipitals_ (13) form the entire boundary of the foramen magnum except the narrow ventral portion formed by the basioccipital. Each exoccipital is a wing-shaped bone, articulating dorsally with the squamosal and supraoccipital, ventrally with the quadrate, basioccipital, and basisphenoid, and anteriorly with the opisthotic. It is pierced by five foramina, four of which were described in connection with the lateral view. Some distance laterad and somewhat dorsad to the pair already described is the fifth and largest foramen (VII); it really lies between the exoccipital and quadrate, but the former bone forms almost its entire boundary; through it, according to Reynolds, pass the seventh nerve and certain blood-vessels. [Illustration: FIG. 22. POSTERIOR VIEW OF THE SKULL OF A. MISSISSIPPIENSIS. 7. squamosal. 8. quadrate. 10. pterygoid. 11. transpalatine. 12. quadratojugal. 13. exoccipital. 14. basioccipital. 15. foramen for carotid artery. 23. parietal. 26. supraoccipital. VII. foramen for 7th nerve and certain blood-vessels. _bs_, position of basisphenoid.] [Illustration: FIG. 23. LONGITUDINAL SECTION THROUGH THE SKULL OF AN ALLIGATOR (_Caiman latirostris_). ×¹⁄₃. (Brit. Mus.) (After Reynolds.)