IG TOMBS OF THE CALIPHS. 



the river. On our way home we stop to examine the 

 quarries of white hmestone, and soon fill our pockets with 

 a rich harvest of fossils : a small species of Crab {Portutius 

 leucodon) is tolerably plentiful ; univalves and bivalves of 

 many kinds are abundant ; and we meet with several of the 

 saw -shaped spines of an Echinoderm {Cidaris veronensis), 

 and, of course, quantities of Nummulites, which are the 

 characteristic fossils of this formation. Yesterday we pur- 

 chased of the Arabs several of the fine Miocene Echino- 

 derms {Clypeaster agyptiacus) which they always bring to 

 the traveller at the Pyramids, and also a piece of white 

 limestone filled with small Nummulites. Our dragoman, 

 always anxious to explain every thing, told us that the 

 builders of the Pyramids had been fed upon lentils, and 

 that this was a piece of their bread made of that seed, but 

 that time had hardened it into the stony substance which 

 we then held in our hands. Although he tried hard to 

 persuade us that he was right, we could not induce him 

 to taste our specimens of nummulitic limestone. 



Near the Tombs of the Caliphs, which we pass on our 

 way to the town, we see numbers of the Egyptian Vulture 

 {Neophron percnopterus), the natural scavengers of the Arabs 

 outside the town, while the dogs perform that office within 

 the gates. The Tombs of the Caliphs are very picturesque, 

 each with its dome ; they are built of red sandstone, which 

 imparts to them such a sameness of colouring with the 

 surrounding desert tliat it detracts somewhat from their 

 real beauty. This want of variety in the colouring is the 

 great drawback to Egyptian scenery. 



February \^tli. — Having got our supplies on board the 

 dahabeah and laid in a good store of powder and shot, we 



