151 



The Middle Coral bed is included in the Oolite Marl, which 

 resembles indurated Chalk, and is interstratified between the 

 Lower and Upper Freestones, forming a division between 

 them. It has a peculiar lithological character, being a kind of 

 Mudstone which, when exposed to atmospheric agency, breaks 

 up into cuboidal masses. In some localities, as at Frith, 

 Leckhampton, Sheepseombe, Swift's Hill, and others, it contains 

 masses of Corals of the genera Thamnastroea and Isastrcea. 

 Sometimes it is largely charged with Brachiopoda, as Terebratula 

 fimbria, T. maxillata, T. carinata, and Bhynchonella Lycetti ; and 

 at Scar HiU, near Nailsworth, it becomes a fine argillaceous 

 Limestone, containing numerous long spiral univalve sheUs, of 

 the genera Nerincea, Ghemnitzia, &c. The Oolite Marl forms a 

 persistent bed in the northern and middle Cotteswolds, extending 

 across this portion of the plateau from the vales of Moreton 

 and Bourton on the east, to the escarpment overlooking the 

 Severn valley on the west ; thinning out and disappearing in the 

 southern part of the range. 



The Upper Coral reef occupies the horizon of the Upper 

 Trigonia Grit, zone of Ammonites ParMnsoni, and is very well 

 exposed in many sections ; that of Cleeve Hill (already referred 

 to) may be consulted, as it has yielded the best Corals I have 

 obtained from this bed, and these are figured as type-specimens 

 in the monograph. The following section is open near 

 Frith, and may assist the correct reading of the beds in this 

 locality. Ascending the bank above this quarry for a short 

 distance, some fields of arable land are passed over, in which 

 are several heaps of the Upper Eagstones with Trigonia costata, 

 Grypluea subloba, and other shells of the higher zone. Walking 

 in the direction of the Grove, after passing over the summit 

 of the hill, we descended for a short distance, and at the 

 right hand side of a bridle-road came to Worgin's Quarry, 

 overlooking the Slad VaUey, in which there is a very good 

 section of the upper reef. 



