54 GASTEROPODA OF THE INFERIOR OOLITE. 
places, and notably near Doulting and Cranmore, under the very shadow of the 
Mendips, thick beds of freestone of Inferior Oolite age, as also at Old Ford, near 
Frome. The well-known section at Vallis, where something like fifteen feet of 
Inferior Oolite rests on the Carboniferous Limestone, seems to show that only beds 
of the age of the Clypeus-grit were deposited upon the old ridge at that spot. 
Why the vicinity of the old reef should have been unfavorable to the accumula- 
tion of shell-beds with Gasteropoda is very difficult to say. But we find in all 
cases the border regions to be less rich than the central parts of the several dis- 
tricts or basins. 
Devas or THE Corresworp Disrrict. (No. 2.) 
In a sense strictly topographical the country between Frome and Bath can 
scarcely be regarded as forming part of the Cotteswold Hills, though, to a certain 
extent, a physical continuation of that range. The exposures of Inferior Oolite 
throughout this portion of No. 2 District are neither numerous nor important in a 
palzontological sense. We have already seen that thick beds of pale-coloured 
oolitic rock (freestones) on both sides of the Mendips replace the rich shell-beds 
and ironshot Oolites of No. 1 District. This phase continues for some distance 
north of Frome. The evidences of Gasteropoda are slight, yet not devoid of 
interest ; there is, however, one great drawback, viz. that most of these fossils are 
in the condition of casts. The high ground north of Radstock is capped by a sort 
of plateau of Inferior Oolite, and here the following exposures were examined. 
Cran Down.—One and a half miles north-west of Radstock. There are several 
shallow pits on this down, where the upper beds of the Inferior Oolite have been 
worked. Of the general development of Inferior Oolite at this spot, and whether 
there is any representative of the Lower Division, Iamignorant. The unconformity 
must be considerable, since the Inferior Oolite is represented in the Survey map as 
resting on Lower Lias ; in one pit, where seven feet of beds are exposed, the upper 
portion consists of a shivery whitish limestone with a variety of Terebratula globata 
scattered about, and containing a shell-bed with Zrigonia and Nerina in casts, 
also Natica Bajocensis and a small Trochus. Below this is a much harder block 
of stone. Nerinea occurs in casts, rather numerously at the top, and also in a 
shell-bed lower down. There is more than one species, but Nerinea Guisei is 
most probably one of them. As we shall see subsequently, this is a very well- 
marked horizon in the Olypeus-grit, and it is extremely interesting to have obtained 
proofs of it thus early in our examination of the Cotteswold District. As far as 
we know at present, this is the most southern locality in England where Neringa 
has been found to occur in the Inferior Oolite, and abundantly too, since there are 
no less than three shell-beds traceable here. | 
