DEVELOPMEXT OP THE SKULL IN THE CEOCODILIA. 307. 



Fig. 6. The same (2nd section), behind external nostrils, X 8 diam. 



Fig. 7. The same (3rd section), through middle of nasal capsule, X 8 diam. 



Fig. 8. The same (4th section), through turbinal folds, X 8 diam. 



Fig. 9. The same (5th section), through rhinencephalic recess, X 8 diam. 



Fig. 10. The same (6th section), through antorbital wall, X 8 diam. 



... PLATE LXVII. 



Fig. 1. Alligator viississipensis (as in last Plate, 7th section). Through fore part of 



eyeball, X 8 diam. 

 Fig. 2. The same (8th section), through orbito-sphenoids, x 8 diam. 

 Fig. 3. The same (9th section), through middle part of eyeballs, X 8 diam. 

 Fig. 4. The same (10th section), through hind part of eyeballs, X 8 diam. 

 Fig. 5. The same (11th section, part), through prepituitary region, X 8 diam. 

 Fig. 6. The same (12th section, part), through pituitary regiou, X 8 diam. 

 Fig. 7. The same (13th section), through alisphenoid, X 8 diam. 

 Fig. 8. The same (14th section), through auditory capsules, X 8 diam. 



PLATE LXVIII. 



Fig. 1. Alligator mississipensis (2nd Stage). Additional {partial) view of .subhorizontal 



section of the head (as in PI. LXIV. figs. 1-4), No. v, through first cleft and 



first and second arches, x 18 diam. 

 Fig. 2. The same (No. vi), a similar section, X IS diam. 



Fig. 3. The same (No. vii), through notochord and pituitary body, x 18 diam. 

 Fig. 4. The same (No. viii), through quadrate and hyoid, x 18 diam. 

 Fig. 5. The same (No. ix), through hinge of mandible, X 18 diam. 

 Fig. 6. The same (No. x), a similar section, higher up, X 18 diam. 

 Fig. 7. The same (No. xi), through Meckel's cartilage and hyoid, X 18 diam. 

 Fig. 8. The same (No. xii), through the same parts, higher up, X IS diam. 

 Fig. 9. The same embryo. Outer view of quadrate, part of mandible, and hyoid arch, 



X 16 diam. 

 Fig. 10. Crocodilus lialustris (3rd Stage): If inch long. The same arches, X 12 diam. 

 Fig. 11. Part of same object, X 24 diam. 

 Fig. 12. The same species (4th Stage) ; embryo, 3| inches long. The same arches, 



outer view, x 7j diam. 

 Fig. 13. The same object, inner view, x 7j. 

 Fig. 14. Part of same object, inner view, x 14J diam. 

 Fig. 15. Alligator mississipensis (5th Stage) : embryo, i\ inches long. Hyoid arch, 



inner view, X 12 diam. 

 Fig. 16. Part of hyoid arch of another specimen of same, X 12 diam. 



