68 



WEALD, OR OAK TREE CLAY. 



respects with the viviparfe of the Sussex marble, are of a more slender 

 and elegant form, and certainly belong to a distinct genus. In short, 

 after repeated examinations of the Weald clay with its imbedded lime- 

 stone, in various parts of its course through Sussex, I have no hesita- 

 tion in stating my conviction, that it is perfectly distinct from the Pur- 

 beck, and is separated from it by the iron sand formation, as represented 

 in the annexed diagram : 



a. ^Veald clay, and Sussex marble, 

 limestone. 



b. Iron sand. 



c. Purbeck 



