86 
THE GEOLOGIST, 
never occurs below the " ragstone," it forma a distingnishing mark of 
the upper zone. In the neighbourhood of Minchinhampton, Mr. Lycett 
has noticed another and higher stratum, probably the equivalent of the 
" Clypeus grit " of Mr. Hull, which he designates " Pholadomya grit." 
Mactra gibbosa occurs in it, and numerous specimens of Terebratula 
globata. If we include the basement-beds, the total thickness of the 
Inferior Oolite is not less than 230 feet at Leckhampton Hill ; of 
which, nevertheless, it does not form the main part, as there is a much 
greater thickness of Lias between its outcrop and the level surface 
of the plain.* This holds good with regard to the outer edge of the 
Cotswold chain, in its entire range over a considerable area. On the 
south and east, the Inferior Oolite is much reduced in thickness, and, as 
we have shown, subject to considerable variations, both in bulk, struc- 
ture, and fossil contents ; some beds being altogether absent or replaced 
by others; and, if rich in organic remains at one spot, are entirely 
destitute of them at another. Jfotwithstanding the depths and con- 
ditions of the sea frequently varied during the period of its deposit, 
there is one striking similarity in the beds of this division: viz., 
the almost entire absence of any terrestrial or fluviatile animals 
or plants. Marine shells and corals of several genera are the 
prevailing fossils, though remains of fish and saurians have been dis- 
covered — the latter very rarely. The student will do well to spend 
some days at Cheltenham, whence he will be able to make excur- 
sions to the chief points of geological interest in the neighbourhood, 
among which may be mentioned Leckhampton, Crickley, Birdlip, Cold 
Comfort, Lincover, Cleeve Cloud, Sudeley, and Bredon — all within an 
easy reach of that town. Further on, in an easterly direction, he may 
visit the numerous quarries by Andoversford, Naunton, Stow, Stanway, 
Burford, and Broadway. Southwards he should examine the country 
in the neighbourhood of Stroud, especially the quarries at Kodborough, 
Selsby, Painswick, Haresfield, Sheepscombe, and Frocester. 
We must now say a few words on a very interesting series of deposits, 
which we have designated the " Ammonite and Bclemnite beds " f 
("Cephalopoda-bed " of W'right), which, though much reduced in thick- 
* The entire formation, except where locally affected byfaults, has a gentle 
dip to the south-east. 
■\ "On the Basement Beds of the Inferior Oolite in Gloucestershire," by the 
Rev. P. B- Bi'odie. — Journal of the Geological SocicUj, 1851, p. 208. 
