PEOCESS-BLOCKS Al^D OTHER ILLUSTRATIVE FIGURES 

 BESIDES THOSE IN THE PLATES. 



Page 

 Fig. 1, Supposed bammerstone of flint from tlie Piltclown Gravel ... 2 



2. Frontal pole of an endocranial cast of Eoanthrcpus, viewed * 



from the front 8 



1. Plan of instrument used in surveying and levelling the 



surfaces of septa and whorls [of Ammonites] 28 



2. Section of the same instrument 29 



3. Graph shovfing the average profile of the adult septum of 



D act ylioc eras commune 31 



4. Contoured plan of the adult septum of Dactylloceras 



commune ^, 32 



5. Last two suture-lines of two ammonites showing the last 



suture incompletely formed 35 



6. Contoured plan of the second septum of Bactylioceras 



commune 36 



7. Graph illustrating the average profile of the second septum 



of Dactylioceras 37 



8. BwiviYQ-\\r\e oi Bactylioceras nnd. Cotloceras 39 



9. Deyelo^mQui oUhe sxxixxi'e-lmQ o^ Bactylioceras commitne ... 42 



10. Series of septal sections made from one of the latest septa of 



a Bactylioceras 43 



11. Section of whorl along' the datum-plane of the sau^e 



septum 44 



