334 



The Geology of Devizes. 



Cretaceous nomenclature : one is to find a new name for the group 

 of beds now called Gault and Upper Greensand; the other is to 

 adopt the name which is used for some of the equivalent beds in 

 France. The first plan is, I think, the better one, but, unfortunately, 

 it is very difficult to find a name that is both appropriate and eu~ 

 phonious. Fitton, when opposing the introduction of the names 

 Upper and Lower Greensand in 1824. suggested " Merstham Beds" 

 for the former; but a compound name is inconvenient, and an 

 adjectival form analogous to Vectian would be much better. 



Now there is no place more fitted to serve as a type locality than 

 Devizes, for — as we have seen in the first part of this paper — both 

 the Gault and the Greensand facies are well developed, the fossils 

 they contain afford a basis for establishing a complete succession of 

 zones, and there are many good exposures of the strata in the 

 immediate neighbourhood of the town. 



The town of Devizes does not appear to have had a very ancient 

 origin ; there is no evidence of its having been a Roman settlement, 

 and it is not mentioned in Domesday Book. From papers written 

 by Canon Jackson and Canon Jones, and published in this Magazine 

 (vol. ix., p. 31, and vol. xvi., p. 255) it would seem that the town 

 sprang up round the castle built by Bishop Roger circa 1130. In 

 order to obtain a site for this he took a slice out of each of the two 

 manors that belonged to him (Bishops Cannings and Potterne) at 

 the point where they met and where the King's manor of Rowde 

 also met them ; the castle built at this point was called " Castrum 

 ad divisas," i.e., at the branching of the boundary lines. The place 

 was long called " The Devizes," and as the name was not a Roman 

 one we need not recur to the strict Latin spelling in forming an 

 adjective, but may use a Latinised form of the modern name, 

 namely, Devisian. 



The other alternative, of adopting one of the French names, would 

 Kave the advantage of avoiding the introduction of a new name, but 

 it so happens that, though the French Cretaceous series is similar 

 to ours, the French geologists have divided it in a different manner. 

 They place the beds which answer to our Gault and Greensand 

 partly in the Albien and partly in the Cenomanien etage, and they 



