The Lenham Sandstones of Kent. 



325 



geology by Mourlon, 1 who regarded it as including Lyell's "Upper 

 Miocene" and Dumont's " Pliocene Diestien ". It was recognized as 

 comprising two divisions or zones, the first characterized by Panopcea 

 menardi, and the second by Glycymeris \_Pectunculus~] pilosa, both of 

 which are now included in the Anversian stage, or " Crag Noir ", of 

 the Belgian Miocene, which is developed at Edegheni and Antwerp. 

 These two Pelecypods occur in the Vindobonian strata of Europe, 

 P. menardi being found as well in the Lenham Beds, Box-stones, and 

 Coralline Crag beds, whereas Glycymeris pilosa is found present in 

 the same horizons, being likewise a member of the St. Erth fauna. 

 Although acknowledging certain differences in the faunas of these 

 Upper Tertiary horizons, which may be probably accounted for by 

 different conditions of environment, no great disparity of time need 

 be allowed for in considering their geological age. I am induced, 

 therefore, from a knowledge of their conchology, to regard the 

 Coralline Crag, 3 the St. Erth Beds, and the Lenham Beds of Britain, 

 together with the Diestian and the Anversian of Belgium, as of 

 Upper Miocene age, and belonging to the stage Messinian or Mio- 

 Pliocene, while the Box-stones, or Nodule beds of East Anglia, 

 I should consider as referable to the Vindobonian division of the 

 Middle Miocene. 



In accordance with these views, therefore, the following synopsis 

 of the various geological horizons referred to is now proposed : — 



Recent 

 Post-Pliocene 



Pliocene 



itish and Mediterranean Seas. 



Upper Miocene or 

 Messinian 

 (= Pontian or 

 Mio-Pliocene ) 



Middle Miocene 

 ( = Vindobonian) 



Lower Miocene 



Glacial, etc. 



{Norwich Crag 

 Eed Crag ( = Astian of 

 Scaldisian of Belgium) 

 Coralline Crag . 

 Diestian 



St. Erth Beds (Cornwall) 

 Lenham Sandstones . 

 Anversian ( = " Crag Noir ' ' of Edeghem 



and Antwerp) . 

 Upper Miocene . 

 ( Redonian ( = Tortonian or Anversian 

 J Box-stones ( = Bolderian of Belgium) 



v. Helvetian-Tortonian . 



Italy and \ Britain. 



Belgium. 

 Britain. 



>- Belgium. 



Germany (N.). 



France (N.W.). 



Britain. 



f Italy, Vienna 



-j Basin, Holland, 



\ Denmark, etc. 



fBurdigalian France (S.W.). 



\ Aquitanian ..... Italy. 



1 Geologie de la Belgique, vol. i, p. 261, 1880. 



2 The foraminiferal evidence, also, lends support to the view that the 

 Coralline Crag is of older age than has yet been accepted. According to 

 the Monograph on the Crag Foraminifera by Jones, Burrows, and others 

 (Palseontographical Society, 1897, p. 369) the following species are recorded 

 from the Coralline Crag of Sudbourne : Nummulina planulata, Amphistegina 

 vulgaris, Operculina complanata, and Orbitoides aspera, formerly determined 

 as O. faujasi. These are said to be " derived from earlier beds", although 

 from a recent examination of the specimens, which are in the Geological 

 Department of the British Museum, they present the appearance of having 

 been found in situ. However, the so-called Nummtdina might indicate an 

 Eocene or Oligocene horizon, but the other organisms are characteristically 

 Miocene, especially when it may be stated that in Orbitoides aspera, after 



