AND DEVELOPMENT OF THE BIRD'S SKULL. 153 



Plate XXV. 



Fig. 1 . Upper beak and nasal opening of Falco tinnunculus (nestling) . x 3 diameters. 



Fig. 2. The same in section, seen from the inside, and half the inferior turbinal showing. X 3 diameters. 



Fig. 3. Nasal capsule of same, with bones removed, from below, x 3 diameters. 



Fig. 4. The same in longitudinal section, x 3 diameters. 



Fig. 5. Transverse section of same, through the beginning of the inferior turbinal. x 6 diameters. 



Fig. 6. Transverse section of same, through alse nasi, x 6 diameters. 



Fig. 7. Palate of Accipiter nisus (fledgling), x 4 diameters. 



Fig. 8. Part of same, side view, x 4 diameters. 



Fig. 9. Part of palate of Helotarsus ecaudatus. Nat. size. 



Fig. 10. Part of palate of Asio otus, lower view, x 3 diameters. 



Fig. 11. Similar figure of Ketupa ceylonensis. x 2 diameters. 



Fig. 12. Vomer of Falco peregrinus (?), side view, x 3 diameters. 



Fig. 13. The same, under view, x 3 diameters. 



Fig. 14. Vomer of Neophron percnopterus , from below, x 3 diameters. 



Fig. 15. The same, side view, x 3 diameters. 



Fig. 16. Pterygoid of same bird, x 3 diameters. 



Fig. 17. Part of palatine of Gyps fulvus, upper view. Nat. size. 



Fig. 18. The same, from below. Nat. size. 



Fig. 19. Palate (part) of Sarcorhamphus papa, from below. Nat. size. 



Fig: 20. The same in Strix stridula. x 2 diameters. 



Fig. 21. Part of same, oblique view, x 4 diameters. 



Note. — The letters mspg in fig. 20 and mpa in fig. 21 refer to the same bone ; fig. 21 is inverted (by mistake). 



Plate XXVI. 



Fig. 1. Skull of Gavia ridibunda (first nestling), side view, partial, x 3 diameters. 



Fig. 2. Same, from below, x 3 diameters. 



Fig. 3. End view of same, x 3 diameters. 



Fig. 4. Hinder part of mandible of same, outer view, x 3 diameters. 



Fig. 5. Same, from within, x 3 diameters. 



Fig. 6. Hyoid of same specimen, x 3 diameters. 



Fig. 7. Nasal labyrinth of same. X 5 diameters. 



Fig. 8. Transverse section of nasal vestibule of same. X 20 diameters. 



Fig. 9. A like section, further back, x 20 diameters. 



Fig. 10. Another section still further back. X 20 diameters. 



Fig. 11. A longitudinal view of the inside of the skull of second nestling (partial), x 3 diameters. 



Fig. 12. A similar (perfect) section of the skull of fourth nestling. 



Fig. 13. Section of alae nasi of fourth nestling. X 20 diameters. 



Fig. 14. Section through ethmoid of fifth nestling, x 5 diameters. 



Fig. 15. Section near " notch" of ethmoid of fourth nestling, x 5 diameters. 



Fig. 16. Another section of same, through interorbital septum, x 5 diameters. 



Fig. 17. A like section, behind the fenestra, x 5 diameters. 



