• O GEOLOGY OF THE ISLE OF WIGHT. 



extinct species of elephant, rhinoceros, horse, buf- 

 falo, elk, deer, &c. ; an assemblage of organic 

 remains common in similar deposits in other parts 

 of England and on the Continent.* 



In the county of Surrey the subsoil of the dis- 

 trict traversed by this railway in many parts con- 

 sists of thick beds of gravel, in which fossil bones 

 and teeth of elephants, horse, and deer, have been 

 discovered ; but remains of this kind are more 

 abundant in the loam and clay. The gravel is 

 almost entirely formed of broken chalk -flints, 

 worn by the action of water into boulders, peb- 

 bles, and sand. It abounds in siliceous fossils of 

 the chalk, and an interesting series of the sponges, 

 zoophytes, and echini of that formation may be 

 collected from the pits around the metropolis. - } - 



Strata of the London basin. — The ter- 

 tiary or eocene strata of the London basin which 

 lie beneath the accumulations of drifted materials 

 above described, and liil up a depression of the 

 chalk (see Han, 1, p. 71), are divided into three 

 groups; viz. 1, Bagshot sands ; 2, London dan; 

 3, Plastic clay. The uppermost \ consists of beds 



■ See Wonders of Geology, fifth edition, vol. i. p. 145. 

 t The flints of the gravel often enclose beautiful examples of the micro 

 scopic fossils which abound in many of the siliceous nodules of the chalk : 

 the most interesting specimens of fossil animalcules in my cabinet 

 obtained from the gravel <>n Clapham and Wandsworth commons. 



tiol sands; so called from the district over which they are most 

 widely expanded. 



