DRIFTS OF FLAMBOEOUGir HEAD. 411 



The value and equivalents of these divisions will now be con- 

 sidered. 



1. Tlie '^ infra-Glacial'^ Beds. — Starting with the lowest beds, we 

 are met at the very outset by a debatable question of the highest 

 importance. Are these beds of Sewerby and Speeton, bein^ older 

 than the Basement Clay, to be considered as older than the Glacial 

 period, or are they, as has been argued *, of inter-Glacial age, 

 formed during an interval between two periods of glaciation ? 



My own opinion, as set forth in a recent paper t, is that the 

 Basement Clay represents the earliest glaciation which affected the 

 eastern side of England, and therefore that the formation of the 

 beds which lie below it preceded that glaciation, though the interval 

 between them may have been brief. 



As to the physical conditions of the period, the "infra-Glacial" 

 deposits indicate an open sea running in farther west on both sides 

 of the headland than at present, a bare chalk wold, and a moist 

 and comparatively mild climate. The fauna of the beds, as at 

 present worked out, in spite of the abundance of specimens, is un- 

 fortunately rather meagre in species, as the following lists will 

 show : — 



Fossils of the Seiverhy CUff-heds i. 



Elephas antiquus, Falc. 



lihinoceros leptorhinics, Cuv. 



Hippopotamus amphibius, Linn. 



Cerviis (? meyaceros, Hart). 



Bison, sp. 



Htjcena (crocuta, var. spelcea ?), Qoldf. 



Arvicola amphibius, Liuu. • 



Birds. 



Gadiis morrhua, Linn. 



Land MoUusca. 



Helix hispida, Linn. 

 Helix palchclla, Miill. 

 Pujja liMryiiuita, Drap. 

 Zua subct/liuclrica, Linn. 



Marine MoUusca. 



Purpura lapillus, L. 

 Littorina littorea, L. 

 Ostrea edulis, L. 

 Mi/tilus edalis, L. 

 Pholas and Haxicava, indicated 

 by borings. 



* Survey Mem. ' Holderness,' pp. 48 and 69. 



t ' (ilacial Sections near Eridlnigtou,' pt. iv. supra cif. 



l ' Final Report of the Committee,' &c., Brit. Assoc. Reports for 1890 (Leeds). 

 Elephas primiyenius appeared in one of the earlier lists, but proved to be 

 based upon an erroneous determination. Tlie abo\e list has been verified, so 

 far as the Mammals are concerned, by Mr. E. T. Newton. 



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