xl INTRODUCTION. 
of this East Yorkshire formation with Wealden rocks of North- 
West Germany, England, and North France is expressed in 
tabular form as follows!:— 
FOUR ZONES OF SPEETON CLAY. 
S. ENGLAND AND 
N.W. Germany. BovuLoene. 
Hils beds with Crioceras Emerici, etc., etc. Weald clay 
Hils clay with Hoplites regalis, etc., etc. Hastings sands. 
Upper Portlandian, brackish | Hils grit and con-| Upper  Portlandian, 
or Purbeckian type| glomerate with] brackish or Pur- 
(Wealden of German geo- |  Belemnites lateralis, beckian type. 
logists). etc. 
Serpulite 
Minder Mergel 
In another recent work, ‘‘Text Book of Comparative Geology,” 
by Kayser (translated and edited by Lake), we find this extremely 
WEALDEN. 
| GERMANY. ENGLAND. 
| Uppers ssc. Wialderthon tessscs-ereus: Weald clay o...ce..00 
en 
| Middle ......| Deister sandstone ......... Hastings sands ......... 
| ee [ESerpmlite. o.css.cwatecers Purbeck 
hecssiestnareege se Miinder Mergel ......... 
simple table in which the term Wealden is used in the wider sense.? 
Having thus defined the term Wealden as employed by some of 
the most recent writers, and stated the sense in which it is used 
1 Arg. Speeton, pp. 200-201. 
2 p. 288. 
