OF CREATION. 



241 



character and habit of this kind, for it gives a 

 reality to the investigations of the palaeontologist, 

 and a familiarity and homeliness to his descriptions, 

 which cannot fail to be pleasing and satisfactory. 



Bivalve as well as univalve shells are found abun- 

 dantly, but not universally, in the chalk ; and some 

 districts in the south of France seem to be remark- 

 able for the singular and extreme development of one 

 group, of which, so far as can be told, there are no 

 living representatives. Their shells were perma- 

 nently fixed to some solid body. The structure 

 of the shell is peculiar and of great thickness and 

 strength, from which we may safely conclude that 

 the animal had no need of motion when once es- 

 tablished in its house. One such genus is called 



Fig. 97 



Sphcerulite, another 

 is the Hippurite ; 

 but there are seve- 

 ral belonging to this 

 group, and they seem 

 most nearly allied 

 to the inhabitants 

 of those univalve 

 shells of which the 

 limpet is the pre- 

 sent representative. 

 I have figured a spe- 

 cies of Sphserulite, 

 to give an idea of 

 the ancient form of the shell of this group. 



Three common and characteristic forms of creta- 

 ceous bivalve shells are also figured. One of them, 

 called Inoceramus (fig. 100), is a shell whose remains 



SPHJERULITE. 



