250 



THE WONDERS OF GEOLOGY. 



Lect. III. 



found in the London Clay, and other tertiary deposits ; 

 the greater number are extinct, or at least unknown to 



fa 



1 3^ 



Lign. 42.— Fossil Shells, from the London Clay, at Primrose Hill. 

 (Collected and described by Mr. Wether ell.) 

 Fig. 1. Two specimens of Vermetus Bognoriensis : natural size. 



2 and 3. Portion of the same magnified, to show more distinctly two minute 



Rotalice which adhere to them. 

 2* Magnified views of the smaller Rotalia, seen in profile, and laterally. 

 3* The same of the larger specimen. 



naturalists. As the external configuration of the shell or 

 crustaceous covering of these animals, is conformable to the 

 soft parts it incloses and protects, the form and size of the 

 principal viscera, as the heart, stomach, &c. may be ascer- 

 tained from the markings impressed on the case ; and thus 

 the character of a fossil species, and its relation to living 

 types, may be determined by the experienced zoologist, 

 from an examination of the carapace and other parts 

 of the shell. Many very beautiful fossil crabs and 

 lobsters have been collected from the clay in the Isle of 

 Sheppey ;* some of which are figured and described by 

 Mr. Parkinson,f and M. Brongniart.J In the tertiary 



* Medals of Creation, vol. ii. p. 530. 



f Organic Remains of a Former World, vol. iii. 



\ Histoire Nat. Crust, Fobs. pi. viii. figs. 5 and 6. 



