142 THE BATH OOLITE PERIOD. CHAP. 



e. Ragstone ... 38 feet thick. 



d. Upper freestone . . 34 f 

 Inferior oolite { c. Oolitic marl ... 7 



b. Lower freestone . . 147 g 



a. Pea-grit . . . .38 

 r Cephalopoda bed ... 8 



Upper lias { Sands 20 



I Blue shale .... 202 

 Middle lias Marlstone . . . .115 



Lower lias probably exceeding . . . 500 



The reader may now turn to the vertical sections given in 

 Plate V, for an example of the rapid thinning, towards the south- 

 east (from Gloucestershire to Oxfordshire), of all these strata the 

 Inferior oolite, in fact, almost disappears. The same thing appears 

 in the longitudinal sections in Plate IV, from Cleeve and Broadway 

 towards Oxford. 



The Pea-grit^ the lowest of the five divisions of Mr. Hull, derives 

 its name from the character of its substance ; for it is composed 

 mainly of flattened spheroidal masses of the size of peas. It is a 

 very large grained oolite a pisolite each mass enclosing an 

 organic fragment which served for a point of concentric attraction 

 to the concreting mass of carbonate of lime. But some of the 

 spheroids appear to be merely worn fragments. This curious 

 * basement bed' is of only limited extent, to the south and north 

 of Cheltenham. It is specially rich in corals, echinida, and 

 crinoids, none of which occur in the cephalopoda bed below, while, 

 unlike that bed, it contains but few ammonites, nautili, and 

 belemnites. Other mollusca are plentiful in the pea-grit. The 

 lower part, which contains much iron oxide interposed among 

 oolitic grains, is 'treated as a separate member by Dr. Wright in 

 his notice of Cleeve-Cloud Hill h . 



The Lower Freestone of Mr. Hull has furnished immense supplies 

 of valuable building stone, from Painswick to Cleeve and Broadway, 

 and from Bourton-on- the- Hill to Naunton and Guiting. The build- 

 ings constructed of it are durable, the stone hardening by exposure 

 from a state of softness, when taken from the quarry, which allows of 

 separation by the toothed saw. The texture is oolitic; there are 

 many small fragments in the mass, especially parts of echino- 

 dermata, and it yields a large series of other fossils, especially 



f 28 feet in the text. & 127 feet in the text. 



b Presented to the Cotswold Club, 1865. 



