﻿482 MESSES. WHITE AND TEEA.CHER ON THE [Aug. I905, 



impoverished fauna, such as is too often the case in the rocks of the 

 same age farther westward. The palaeontological facies of the 

 Marsujpites-Be&a of this section is scarcely less peculiar than 

 the lithological ; and if, in the latter case, the peculiarity does not 

 wholly consist in a mineralogical accession to the normal Chalk of 

 the zone (but in a group of correlative phenomena, of which the 

 presence of an unusually-large proportion of calcium-phosphate is 

 the most obvious and important), neither, in the former case, does 

 it reside entirely in a zoological depletion. Mr. Strahan, 1 in this 

 country, and the late Prof. Eenard & M. Cornet, 2 in Belgium, have 

 called attention to the prominence offish-remains in all known phos- 

 phatic chalks. A further distinguishing feature of the Santonian 

 and Campanian deposits of this class in North-Western Europe 

 appears to be the abundance of individuals of beleinnites and 

 oysters ; while, so far as we can gather from the literature of the 

 subject, a dearth of many other forms common in the normal chalks 

 is no less a characteristic of the French phosphates referable to 

 those stages than of the single English example. 



The fauna of the Marsupites-Beds of Taplow is, then, in a measure, 

 a special one, adapted to the special, but little-known conditions 

 under which phosphatic chalks were accumulated at widely distant 

 points on the sea- floor, in late Cretaceous times. 



The broader lithological features of the Taplow-Court section so 

 closely resemble those of the phosphate-workings in the North of 

 France, that the descriptions of the latter given by MM. Lasne, 

 Gosselet, de Mercey, and other authors are, in many cases, appli- 

 cable to the former, down to the smallest detail. 



Attention has already been drawn to the similar distribution of 

 certain fossils in the phosphatic chalks of Buckinghamshire and 

 Picardy. How far this parallelism extends we are unable to judge, 

 for despite the formidable dimensions which the literature of the 

 French deposits has assumed during the last fifteen years, but little 

 information is forthcoming on the subject of their fauna. It would 

 seem that the higher phosphatic chalks of Northern France are 

 generally less fossiliferous than ours, but the frequent allusions to 

 oysters, belerunites, and sharks' teeth, 3 and the occasional references 

 to plates of Marsupites* suggest that a careful search would, in 

 some instances, reveal a succession essentially similar to that at 

 Taplow. The majority of the French deposits must, however, 

 belong to a distinctly higher horizon, for in them Actinocamaoc 

 granulatus seems a comparatively scarce form, 5 while A. quadratus 

 is usually present, and BelemniteUa mucronata not infrequently so. 



1 Quart. Journ. Geol. Soc. vol. xlvii (1891) p. 366. 



2 ' Reeherches microavaphiques sur la Nature & l'Origine des Roches phos- 

 phatides ' Bull, Acad. Roy. Belg. ser. 3, vol. xxi (1891) pp. 126 ei seqq. 



' J See M. Lericlie, ' Revision de la Faune ichthyologique des Terrains 

 cretaces du Nord de la Prance' Ann. Soc. Geol. du Nord, vol. xxxi (1902) 

 pp. 87-154. 



4 For example, J. Gosselet, Ann. Soc. G<§ol. du Nord, vol. xxi (1893-94) 

 p. 349. 



5 Id. ibid. vol. xxix (1900) p. 79. 



