THE ANIMAL KINGDOM. 37 



These nummulites receive their name from their flattened 

 discoidal form, which resembles that of a piece of money, 

 in Latin nummulus. Many of these shells are very small ; 

 others attain the size of a lentil, a seed which they often 

 resemble exactly. 



The nummulites, then, have played a great part at dif- 

 ferent geological epochs. They are met with in prodigious 

 quantities in the secondary and tertiary beds, and they 

 abounded to such an extent in the seas which overflowed 

 some of our continents that their shells, being heaped to- 

 gether, have formed elevations of remarkable extent. 



These shells, extending over a vast area, really constitute 

 the Arabian chain which extends along the Nile. There 

 they are so numerous, and heaped up in such a manner, 

 that there is scarcely any matrix to bind them together. 

 In many regions of Upper Egypt which I have traversed, 

 the soil of the desert consists entirely of a thick bed of 

 nummulites, in which the feet of the travellers and their 

 camels slip and sink deep at every step. 



Paris is, as we have said, built solely of shells ; this is 

 also the case with the Sphinx and the celebrated Pyramids 

 of Egypt. The immense blocks composing the latter, 

 neither the transportation nor the raising of which to such 

 a vast height has been well explained, were brought from 

 the Arabian chain, and are composed solely of nummulites. 

 Many of these exactly resemble lentils in their form and 

 size, and this coincidence has given rise to strange mistakes. 

 Time, wearing down the surface of these gigantic monu- 

 ments, has gathered enormous masses at their bases, where 

 they impede the footsteps of the traveller. In the time of 



