18 Alfred Bell — Age of the Suffolk Boxstones. 



Dr. Nerregaard's list of 64 species, as noted further on, yields 

 16, or 25 per cent, boxstone forms. Mr. Newton's list of 77 species, 

 10 or 11, or about 13 per cent. 



Uavn's list, when closely examined, gives 51 Middle Oligocene 

 species, including 15 boxstone forms or about 30 percent, as compared 

 with Vanden Broeck's 38 per cent. 



These analyses show that the "boxstone" sands are nearer to 

 the Oligocene Argile de Boom than to any of the others; they may 

 be classed, I suggest, as Upper Rupelien. 



De Koninck, in his classic memoir on the fossil shells of Basele, 

 Boom, etc., lias figured or described many of the shells since found in 

 the boxstones ; the above view is strengthened by the presence, both 

 here and in Belgium, of similar types of vertebrates, many Elasmo- 

 branch fishes and Crustaceans, various species of fossil woods, and 

 vegetable debris.^ 



Dr. Clarke noticed the abundance of long thin rolled plaquettes of 

 waterworn bones, which caused Sir E. Bay Lankester to call the 

 deposit in which they occur "the Suffolk bone-bed". They are 

 seldom, if ever, coated with the sandstone matrix, and it is very 

 probable that they did not become mineralized till a later period, as 

 the bony fragments enclosed in the nodules do not show any signs of 

 such action. 



Phosphatization is not confined to age or place, as SirJethro Teall- 

 has pointed out. Professor Herdman ^ says also of certain oysters : 

 " The shells were worn, many were brown in colour and polished, 

 indicating a partial conversion into a phosphatic condition." 



The presence of fossiliferous boulders in the north-west continental 

 area bordering the North Sea is well known. Herr Nerregaard* 

 states he has collected these blocs from a tuilerie near Esbjerg, and 

 although he classes them as Middle Miocene notes that " their fauna 

 differs considerably, in certain respects, from that of the Danish 

 Miocene " (op. cit., p. 46). His list of fossils from these boulders 

 runs into sixty-four species. Sixteen of these, including Cardiimi 

 cingulatum, Turritella Geinitzi, Aporrhais speciosa, and Pleurotoma 

 Steinvorthi, are included in our boxstone fauna. 



Mr. Harmer informs me that Mr. van Waterscboot van der Gracht, 

 the Director of the Geological Survey of Holland, told him that 

 blocks of fossiliferous limestone, believed to be of Oligocene age, 

 were not infrequently dredged by the North Sea fishermen. 



The " fossiliferous limestone block from the North Sea"*, described 

 by Mr. 11. B. Newton, F.G.S., seems to have had a similar history. 

 It "has not suffered a sea change", nor does it show any signs of 

 abrasion or water-action. The stone is, I suggest, older than 

 Mr. Newton makes it, and has been, I think, but recently cleared of 

 the enveloping clay. I am sorry to disagree with his interpretation 



^ Mem. Acad. Eoy. Bruxelles, vol. xi, 1837. 

 ^ Proc. Geol. Assoc, vol. xvi, p. 385. 



' Report on Ceylonese Pearl Fisheries, Eoy. Soc, 1903, p. 348. 

 * " Mellem MiocEene Blookke fra Esbjerg": Dansk. Geol. Foren., vol. v. 

 No. 1, 1916. 



^ Q.J.G.S., vol. Ixxii, 1917. 



