65 



that I could not determine all the species. I noted, however, 

 the following: — 



Chemnitzia Cypricardia cordiformis, Deah. 



Nerinsea Terebratula Etheridgii, Davids. 



Modiola plicata, Sow. Montlivaltia, species. 

 Pecten lens, Sow. 



3. The Zone of Awmionites Murchisonce. 



Synonyms. — Dogger, (pars.) Yoting. and Bird, Geology of the 

 Yorkshire Coast, 1822. Phillips, Geology of Yorkshire, 1829. 

 Central and lower division of the Inferior Oolite, Muechison, 

 Geology of Cheltenham, 1834. Fimbria stage of the Inferior 

 Oolite, LxcETT, Cotteswold HiUs Handbook, 1857. Zone of 

 Ammonites Murchisonce, Wright, Monograph of Oolitic Echino- 

 derms, 1856. 



Description. — This division attains a considerable thickness in 

 the western escarpment of the Northern Cotteswolds, where 

 it consists of thick bedded Oohtic Freestones, frequently over- 

 lain by cream-coloured Marls, or thin bedded Limestones, and 

 resting on calcareo-siHceous Eagstones, largely charged with the 

 Peroxide of Iron, having inter- stratified therewith remarkable 

 beds of Pisolite and Pea-grit, strongly impregnated with the 

 same mineral. 



In the neighbourhood of Cheltenham, as at Cleeve, Dowdes- 

 well, Leckhampton, Crickley, and Birdlip, this zone is well 

 exposed and attains its greatest development, measuring in 

 some places upwards of 200 feet in thickness. 



In the Southern Cotteswolds, the beds become thinner, in 

 proportion as they are traced southwards ; and at Dundry HiU, 

 Somerset, they almost entirely disappear. 



In the Eastern parts of the chain the same result obtains; 

 at Turkdean, near Northleach, the zone is 50 feet thick; at 

 Sherborne, only 5 feet; and near Burford it has entirely thinned 

 out, the Inferior Oolite being there represented by the Ragstone 

 beds of the Parkinsoni zone. At Leckhampton HiU, which may 



