DEVELOPMENT OF THE SKULL Df THE CEOCODILIA. 305 



DESCEIPTION OF THE PK.iTES. 



PLATE LXII. 



Fig. 1. Alligator Jiiississipensis, Daudin (1st Stage): total length 11 lines (head 3, 



body 5, tail 3). Side view of embryo, X 6 diameters. 

 Fig. 2. The same, lower view of head, X 6 diam. 

 Fig. 3. AUigator mississipensis ('Jnd Stage) : total length 1^ inch (head 4 lines, body 6, 



tail 8). Side view of embryo, X 6 diam. 

 Fig. 4. The same, lower view of head, X 6 diam. 

 Fig. 5. Crocodilus palustris. Lesson (3rd Stage) : total length 2 inches (head 6 lines, 



body 8, tail 10). Side view of embryo, X 3^^ diam. 

 Fig. 6. The same, upper view of head, X 3y diam. 

 Fig. 7. The same, lower view of head, X 3i diam. 

 Fig. 8. Crocodilus iKiIustris (3rd Stage): total length 2^ inches (head 5 lines, body 10, 



tail 12). Side view of embryo, x 2f diam. 

 Fig. 9. The same, upper view of head, x 2f diam. 

 Fig. 10. Crocodilus palustris (4th Stage): total length 3| inches (head 11 lines, body 



13, tail 18). Upper view of head of embryo, X 2 diam. 

 Fig. 11. The same, side view of head, x 2 diam. 

 Fig. 12. Alligator mississipensis (5th Stage) : total length i\ inches (head 1 inch), 



X 2 diam. 

 Fig. 13. The same, front view of head, x 2 diam. 

 Fig. 14. The same, upper view of head, X 2 diam. 



PLATE LXIII. 



Fig. 1. Alligator mississipensis (1st Stage). Head of embryo, with lower arches 



removed; lower view, X 12J diam. 

 Fig. 2. The same, with lower surface of base of skull exposed, X 12^ diam. 

 Fig. 3. Alligator mississipensis (2nd Stage). Head of embryo, with lower arches 



removed, X 10 diam. 

 Fig. 4. The same, with lower surface of base of skull exposed, x 10 diam. 

 Fig. 5. The same, base of skull, oblique view, X 15 diam. 

 Fig. 6. The same, dissected head of embryo, upper view, x 10 diam. 

 Fig. 7. The same, head of embryo, in vertical section, X 10 diam. 

 Fig. 8. The same object, with brain removed, x 10 diam. 



3a2 



