VOL. XVII. (I) INFERIOR OOLITE-SOUTH COTTESWOLDS 83 



Dursley, is on its horizon. That is all that can be said and 

 south of Dursley it is perhaps best to designate the beds 

 between the Upper Trigonia-Grit and Scissmn-Beds simply the 

 " Freestone-Beds." From Coaley Wood northwards, however, 

 the Pea-Grit can be traced by way of Frocester Hill to Selsley 

 HiU where it is found to have expanded and to be replete 

 with fossils which at Crickley HiU, near Gloucester, characterise 

 the top-portion of the Pea-Grit. This, combined with the fact 

 that the upper surface of the underlying Lower Limestone is 

 waterworn, and frequently has small oysters attached to 

 it suggests that the lower portion of the Pea-Grit is absent 

 from Selsley, and that the top-portion there rests non-sequen- 

 tially upon the Lower Limestone. The gap is partly bridged 

 over at Rodborough Hill, where massive pisohtic hmestones 

 have come in, and the top-portion has also become more 

 pisohtic. Specimens of Nerincea are frequently abundant m 

 the Pea-Grit, and connect the deposit in which they occur in 

 point of time with the NerincBa-cingenda-Bed of Blea Wyke or 

 Ravenscar, on the Yorkshire coast. 



(xxii.) Lower Freestone (late Mwrc/iisow^).— This rock is 

 of the usual lithic aspect, and— amongst other places— can be 

 studied at the Coaley-Wood Quarry and Frocester Hill. At 

 Selslev Hill it is very indifferently exposed, the paucity of 

 .sections in it probably being due to its inaccessibility, owing to 

 faulting and land-sHding, rather than to non-presence. Witchell 

 thought it might be as much as 70 feet thick, and I see 

 no reason to differ from him. 



(xxi.) Oolite Marl and (xxii.) Upper Freestone [hyadford- 

 ewsis.— These deposits have a less extended geographical 

 distribution than the underlying Lower Freestone, not extend- 

 ing further south on the western face of the hills than Pen 

 Wood, but owing to certain earth-movements are present 

 further south away from the hill-edge in the neighbourhood of 

 Nails worth. 



It is difficult to indicate precisely where the line of 

 demarcation between the Oolite Marl and Upper Freestone 

 comes in the South-Cotteswold sections, and although I have 

 done so where possible, it must be remembered that while the 

 marl usually occupies the inferior position, marly conditions 

 may extend upwards and replace even the whole of the Upper 

 Freestone, as is the case at " The Frith " Quarry, near Stroud. 



