296 OUR COMMON BRITISH FOSSILS. 



CHAPTER XIII. 



FOSSIL CEPHALOPODS. 



I DON'T know any British fossils more common than 

 some of those which come in for treatment in the 

 present chapter. In China a few (like Orthoceras 

 and Ammonites) are used in medicine, for the simple 

 reason that nobody there knows anything about their 

 origin, and their mysterious abundance is taken as 

 an indication of the generative powers of the earth ! 

 Even in Britain they have gained a place in folk-lore, 

 and some have been immortalized in poetry, like 

 the "snake-stones" (Ammonites communis), in Scott's 

 "Marmion." In the Eastern Counties, where they 

 abound although the specimens found there do not 

 rightly belong to the place, for they are " derivatives," 

 torn out of their parent rocks and brought thither 

 during the Glacial period by ice agency, and re- 

 deposited in the boulder-clays they are known by 

 the name of " thunder-bolts." 



Thunder was always more dreadful to uneducated 

 people than lightning, and all over the world there 



