The Lenham Sandstones of Kent. 



323 



Crag and the Diestian beds of Belgium. This is apparent from 

 Mr. Harmer's list of the Diestian species (Quart. Journ. Geol. Soc., 

 1898, vol. liv, p. 317), in which, out of rather more than seventy 

 forms enumerated, nearly all are stated to occur in the Coralline Crag. 



A considerable proportion of the Anversian species of Belgium, as 

 listed by M. "Van den Broeck (Ann. Soc. Mai. Belgique, 1874, vol. ix, 

 pp. 118-121), likewise occur in the Coralline Crag, as out of a list of 

 175 species 80 are recognized as being found in that formation. 



The following table shows the numerical representation of the 

 seventy-seven Lenham species occurring in the principal formations : — 



Eecent ...... 40 species. 



Post-Pliocene .. . . . ' . 23 , , 



Astian . . . . . . 36 ,, 



Plaisancian . . . . . 40 , , 



. Scaldisian . . . . . . 44 ,, 



Norwich Crag 12 ,, 



Eed Crag 48 



(probably derived from Coralline Crag). 

 Coralline Crag . . . . . 51 ,, 



St. Erth 16 



Box-stones. . . . . . 13 ,, 



Diestian . . . . . . 30 , , 



Anversian . . . . . . 34 ,, 



Messinian . . . . ■ . . 25 ,, 



Bolderian . . . . . . . 17 ,, 



Kedonian (Tortonian) . . . . 26 ,, 



Vindobonian (Helvetian-Tortonian) . 47 ,, 

 The so-called Older Pliocene beds of Mr. Keid's memoir are 

 characterized by shells with a southern facies indicating warmer 

 climatic conditions than prevailed in the Bed Crag period, when 

 boreal and Arctic species were largely predominant. The East 

 Anglian Box-stone deposits have been regarded by Mr. Harmer 1 as 

 the probable equivalent in time of the Waenrode Beds of Belgium, 

 which Van den Broeck 2 has considered to be of Bolderian age and 

 therefore Miocene. In this connexion it is interesting to note that 

 the Box-stone beds have been quite recently regarded as Miocene by 

 Mr. Keid. 3 



Sir Ray Lankester 4 determined some Proboscidean remains from 

 those beds as a new species of Mastodon, although subsequently 

 recognizing them as a variety of M. angustidens of Cuvier, 5 being 

 further of opinion that they were older than the Diestian of 

 Belgium. It is well known that Cuvier's species characterizes the 

 older Vindobonian beds of France, and is frequently found in the 

 ossiferous deposits of Sansan. When the Box-stone Mollusca are 

 more studied, such an age as is here indicated will probably be more 

 conclusively proved ; in the meantime the evidence is in favour of 

 those deposits being older than the Lenham Sandstones. The St. Erth 

 deposits of Cornwall were originally described by Searles Wood 6 as- 



1 Quart. Journ. Geol. Soc, vol. lvi, p. 708, 1900. 



2 Ann. Soc. B. Mai. Belgique, vol. xix, pp. lvi-lxvi, 1884. 



3 Mededeel. Eijks. Delfst., 1915, No. 6, p. 9. 



4 Quart. Journ. Geol. Soc, vol. xxvi, pp. 507-9, 1870. 



5 Geol. Mag., 1899, p. 292. 



6 Quart. Journ. Geol. Soc, vol. xli, pp. 65-73, 1885. 



