330 



FOSSIL TEETH. 



calcareous sandstone extends on the southern, western, and north 

 western coast of Australasia, for three thousand miles. Some speci- 

 mens, which 1 have examined with a lens, appear perfectly similar 

 to the recent sandstone from Guadaloupe. 



Among the causes in present activity, which are changing the sur- 

 face of the globe, the labours of madrepores must not be unnoticed. 

 These minute polypi, raise up walls and reefs of coral rock with as- 

 tonishing rapidity in tropical climates, and encircle the present is- 

 lands with belts of coral, thus enlarging their coasts. A coral reef 

 of seven hundred miles in length, extends from the north-west of 

 Australasia, towards new Guinea. For a detailed account of coral 

 rocks and reefs, I must refer the reader to the observations of Dr. 

 Forster, and the voyages of Captain Flinders, and of Kotzebue, and 

 of the French naturalists MM. Quoi and Gaimard, but more partic- 

 ularly to the observations of Captain Beechy, made during his voy- 

 age to the Southern Pacific. The subject of coral reefs has been 

 before referred to at some length. See Chap. VI. 



Organic Remains in Diluvial Beds. — As the remains of the mas- 

 todon, the elephant, the rhinoceros, and hippopotamus occur, with 

 the bones of other mammalia, in diluvial beds, this circumstance 

 proves their great antiquity, and disiinguishes them from alluvial de- 

 positions. Teeth of the latter animals are not uncommon in English 

 diluvium, and two teeth of the mastodon have been found in the Nor- 

 folk Crag. 



It has been thought desirable to give drawings of the teeth, for the 

 use of the geological student. 



The first represents the pointed tooth of the mastodon ; the other 

 the flat crowned tooth of the elephant, which is sometimes larger 

 than that of the mastodon. 



The following cut represents the molar tooth of the rhinoceros, a, 

 from Kirkdale cavern ; b is the molar tooth of the hippopotamus, 

 much worn, from the same locality. 



