330 The Geology of Devizes. 



the Upper and Lower Gault ; but as it is now universally admitted 

 that there is no such comprehensive group as a Middle Cretaceous 

 or " Greensand " formation, it is illogical and inconsistent to speak 

 of an " Upper " and " Lower Greensand." 



The suggestion made by Godwin-Austen in 1850, and more 

 recently (1870) urged by Professor Judd, that the French name of 

 Neocomian should be adopted for the Lower Greensand is equally 

 unfortunate, because the true Neocomian is the equivalent of the 

 Wealden, which underlies the Lower Greensand, and the name used 

 by the French for the beds which represent our Lower Greensand is 

 Aptien. Moreover a good name had been proposed for the British 

 groups before God win- Austen wrote, for Fitton in 1847 had proposed 

 to call the Lower Greensand Vectine, from Vectis, the Roman name 

 of the Isle of Wight ; and nowhere is the group better developed 

 or more conveniently exposed for study than in that island. 



This is the name I have adopted, only altering it to the other 

 adjectival form of Veclian; in it we have a short well-sounding 

 name which does not convey any erroneous ideas and is derived from 

 a well-known locality. 



But, when we have abolished the term Lower Greensand, we 

 cannot continue to speak and write of an Upper Greensand', we 

 must either revert to the original names of Gault and Greensand, 

 or we must find a new name, and first of all we must enquire 

 whether the Gault and Greensand are separate members of the 

 Cretaceous series, or whether they are only different parts or litho- 

 logical facies of one formation — the " Gault " of one locality passing 

 into the " Greensand " of another. 



In this enquiry the fossils of the Devizes Sandstone afford valuable 

 assistance. If the Greensand always contained a similar set of fossils 

 and the Gault always held a different set, and if the characteristic 

 fossils of the one were never found in the other, then there would 

 be good reason for regarding them as distinct subdivisions of the 

 Cretaceous series. This, however, is not the case : at Folkestone, 

 where the Gault is so well exposed and so rich in fossils, there is 

 nothing which can be compared lithologically with the Sandstone 

 of Devizes, but most of the Devizes fossils are found in the upper 



