6o 



lOUkNAI. OK CONCHOLOGY, VOL. 15, NO. 2, APRIL, I916. 



Pelecypoda — 



Area lade a ? 



Peden avicula ? and P. bniei 

 Modiola mod tola ? 

 Pedunculus s;Iycyineris ? 

 N'ucnla nucleus ? 

 Nucula deprcssa Nyst. 

 Leda lanccola/a & L. my a lis} 

 Astarte di^^itaria^ A.pygmcea, 



A. compressa ?, A. omaliil 

 Cardium (with spines) and 



C. editle. 



Cythereci rudis ? 

 Tapes perovalis. 

 Ltitraria elliptica. 

 Crassatella concentrica ? Duj. 

 Tellina donadna ? or Douax. 

 Madra triangulata ? 

 Cardifa, Ludiia or Diplodonta, 



Kellia or I^epton^ Isocardia. 

 Venus ? Anatina, Panopcea ? 



Brachiopoda — 



Terehratula grandis ? 



In the same memoir, Prestwich referred to the occurrence of 

 similar ferruginous sandstones to those at Lenham on the chalk downs 

 between Calais and Boulogne, and at Cassel Hill in French Flanders, 

 515 feet above the sea, overlying the Calcaire Grossiet- series. It was 

 mentioned that such beds, although without fossils, had been deter- 

 mined by Dumont and Lyell as equivalent to the Diestian Sands of 

 Belgium, which they classed with the English Crag, because the same 

 sands had been found at Louvain overlying the Limburg and Bolder- 

 berg strata, containing impressions of shells of Terebratuki grandis, 

 Solen ensis, and Syndosmya prismatica, besides thirteen genera of 

 indeterminable species. In a further reference to the Lenham mol- 

 lusca, Searles Wood^ mentioned that the Pyrula and Pedunculus 

 resembled certain sandstone-casts from the Red Crag (Box-Stone 

 specimens), although a closer determination was not possible from 

 their peculiar preservation. 



Lyell*^ recognised the Lenham beds as of Upper Miocene or F'alu- 

 nian age, and similar to the Diestian Sands of Belgium, and, moreover, 

 probably older than the Coralline Crag. 



He had traced the Diestian beds, which "abound in green grains," 

 from Diest by Louvain and Oudenarde to Cassel in French Flanders 

 and capping the hills of those places — away to the English Downs 

 near Folkestone, and appearing at such places as Paddlesworth, 

 Lenham near Maidstone, etc. He referred to the occurrence in 

 those beds of Terebratula grandis, casts of Astarte, Pyrula, Emarg- 

 inula, which were all common to the British Crag, the first named 

 being specially characteristic of the Belgian Diestian. 



1 On the Exlraneoiis Fossils of ihe Red Crag;: (Jiiar/. Jomn. Ccfl. Soc, 1859, vol. 15, 

 pp. 32—45. 



2 Elements of Geology, 1865, ed. 6, pp. 233 and 366. 



