DORSET-SOMERSET DISTRICT. 53 



The upper beds at Woolston, Shotwell, and Grove contain a scattering of 

 Brachiopoda including Bhynch. spinosa, and in the two latter there is a distinct 

 Terebratula-bed chiefly made up of a variety of T. globata. These beds then 

 would seem to prefigure the Clypeus-grit ; and on this horizon, if anywhere in the 

 Dorset-Somerset District, specimens of Nerincea, which has hitherto failed the 

 collector, should be sought. 



Pitcomb Road. — Two and a half miles east by north of Castle Cary. This is 

 the last exposure in No. 1 District of beds containing any noteworthy quantity of 

 Gasteropoda. It is a small roadside section. Reposing directly upon soft 

 yellow sand-rock, believed to form part of the " Yeovil Sands," is (1) a calcareous 

 or subcalcareous bed with shells, fourteen inches thick; (2) a rich shell-bed with 

 many Cephalopoda and some Gasteropoda, thirty inches thick; and (3) pale- 

 coloured limestones, of which three or four feet are exposed in the road cutting. 

 After the experiences of Grove and Woolston this is certainly a surprise, since this 

 " fossil-bed " is clearly not in the Parkinsoni-zono. The prevailing Ammonites 

 are keeled, and may be on the horizon of those in the Soiverbyi-hed at Bradford 

 Abbas. Perhaps we may obtain further evidence. 



Resume of the North-eastern half of the Dorset- Somerset District. 



One very striking feature is the difficulty of predicating for any given neigh- 

 bourhood on what horizon the main fossil-bed shall lie. All the zones, except 

 perhaps the opalinus-zone, are well represented, and teem with most beautifully 

 preserved Gasteropoda, some in one place and some in another. Consequently 

 this has for years been the favourite hunting-ground of collectors. A very con- 

 siderable proportion of the Gasteropoda selected for description in the accompany- 

 ing Memoir are from this division of No. 1 District, and they are on the whole in 

 by far the best state of preservation. Compared with these the Gasteropoda of 

 the remaining districts are disappointing. 



Border region of the Mendips. 



If we allow, for purposes of delimitation, that the prolongation of the Mendip 

 axis shall be considered to divide District No. 1 from District No. 2, yet there is 

 a considerable portion of the Inferior Oolite outcrop on both sides of this axis 

 which contains no shell-beds with Gasteropoda, and with which we need not 

 trouble ourselves. The country from Bruton to Radstock, a distance of twelve 

 miles if measured in an air-line, but more if we trace the edge of the outcrop in 

 the neighbourhood of Frome, will be comprised in this border region. This 

 presents many features of interest to the physical geologist, containing in some 



