142 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 21, 



laps h for a small space on the south-east, in Essex, and again at 

 Horseheath, near Saffron Walden, but overlaps it altogether on the 

 north-west, resting on the secondary rocks in Huntingdonshire and 

 Lincolnshire. The distribution of h indicates it as the deposit of an 

 irregular bay, afterwards submerged by the sea of a, which over- 

 spread a very wide area, a now remains only in detached tracts, 

 having been extensively denuded on its emergence at the beginning 

 of the post-glacial age, so that wide intervals of denudation (sepa- 

 rating the tracts) indicate the post-glacial straits and seas which 

 washed islands formed of a. The author considers the so-called 

 Norwich Crag of the Cromer coast as not of the age of the Eluvio- 

 marine Crag of Norwich, but as an arctic bed forming the base of c, 

 into which it passes up uninterruptedly. The author regards the 

 beds 6 as identical with the Fluvio-marine gravels of Kelsea, near 

 Hull, and thinks that the Kelsea bed is not above a, as hitherto 

 supposed, but below it, having been forced up through a into its 

 present position. He also regards the Upper Drift (a) as the equi- 

 valent of the Belgian Loess, and the beds h as the equivalent of the 

 Belgian Sables de Campine. 



