Enaliomuria. 



PLATE 1. 



Fig. 

 I — 10, 13 — 16. Teeth of Ichthyosaurus campylodon. 



From the Chalk and Green-sand of Cambridgeshire. In the Collection of 

 James Carter, Esq., of Cambridge. 



11. Back tooth of a recent Alligator, showing the circular hole made by the ab- 



sorption consequent on the pressure of a young tooth. 



12. Tooth of a recent Crocodile, showing the young tooth, that has penetrated the 



pulp -cavity of the old tooth. 



1 7- Tooth of Ichthyosaurus communis, from the Lias of Lyme Regis. 



All the figures are of the natural size. 



