RELATIONS TO OTHER BRITISH DEPOSITS. 57 



have given the list of species elsewhere (see ante, p. 33). Amongst 

 these are Ammonites Martini, Ammonites Deshayesii and Ancylo- 

 ceras gigas, which are all good Upper Neocomian or Aptien species 

 very characteristic of the Atherfield clays — to which beds Mr Wilt- 

 shire has consequently referred the Hunstanton series. But so far 

 as I have seen or been able to learn all the Hunstanton species are 

 ' derived ' fossils, and not native to the stratum in which they lie. 

 They are all either in the condition of rolled phosphatised casts, 

 or are found in the hard rolled lumps of dark iron grit as re- 

 corded ante, so that these fossils instead of proving the bed to 

 be of Atherfield clay age, really shew that it is of some age 

 posterior to that period : — though it is probably not far removed 

 from it. 



Comparing the Hunstanton bed directly with the Upware 

 Nodule bed we find some resemblances between the two litholo- 

 gically, also in the contained phosphatic nodules and pebbles ; and 

 particularly in the species of derived Neocomian fossils. To these 

 points I attach considerable importance, and I consider that, not- 

 withstanding the absence of a true indigenous fauna (they may 

 have once existed there and since been destroyed), we have good 

 reason to consider the Hunstanton and Upware sands and pebble 

 beds as belonging approximately to the same age. 



We have thus been enabled by the study of a number of 

 isolated sections and their fossils to establish the close relationship 

 of the beds of variously coloured sands, coprolite beds and carstones 

 which are exposed, with some interruption, along an outcrop 

 running from the N.E. at the Wash to the S.W. in Wiltshire* — 

 stretching from the neighbourhood of Wicken in Norfolk down to 

 Wicken in Cambridgeshire (!). They are again well developed 

 around Potton and Sandy in Bedfordshire, and are last seen near 

 the villages of Pottern and Sandy in Wiltshire (!!). 



It now becomes a matter of great interest to discover the 

 relation of this set of deposits to the better known and typical 

 districts of the S.E. and N.E. of England. 



In the year 1850 Mr Godwin Austen published a masterly 

 description of the Farringdon and Swindon areas and came to the 



1 The Lower Sands of Shotover Hill, with Freshwater fossils, and the Downham 

 Market coprolite bed excluded. 



