6X4 FAUNAL SUCCESSION OF THE UPPER BERNICIAN 



Notes : — The " Eelvvell" fauna is closely allied to that of the 

 Acre Limestone, but contains fewer Great Limestone forms. 

 The corals, which are very plentiful on the upper surface of 

 the bed at the shore near Beadnell and Sea Houses, are 

 thickened internally and their structure is often obliterated by 

 calcareous matter. In the same locality Prod, loiigispiuus and 

 Spirifer near trigonalis form a band in the shale immediately 

 above the limestone. 



The faunal assemblage is an extensive one. From the 

 Eelwell Quarry, Lowick, the late Rev. Edward Jenkinson 

 obtained many of his specimens, now in the Sedgwick Museum, 

 Cambridge. Fragments of encrinital columns are very num- 

 erous and frequently attain considerable thickness. 



The thin limestone lying below the North Sunderland or 

 Eelwell Limestone, and well exposed on the shore at Beadnell 

 and near Sea Houses, possesses a fauna very similar to that 

 of the thicker bed above it. 



From the above locality I have obtained : — 



Cydophyllnm aff. pachyendothecum. Zaphrentis aff. enniskilleni. 



Lithostrotioii jiinceum. Product us longispinns. 



Caninia sp. Bellerophon sp., large. 

 Caninoid Canipophyllum. 



The Five Yards, Six Yards, and Acre Limestones. 



The limestones referred to by these names, although occur- 

 ring in the south, middle and north of the county respectively, 

 are in all probability one and the same calcareous bed.* 



Geographical Distribution. 



Taken as one bed, the account of geographical distribution 

 of the Great and Four Fathom Limestones equally applies to 

 these limestones. The Five Yards occurs in the Tyne district ; 

 the Six Yards has been mapped from the Wansbeck to 

 Beadnell, and the Acre is met with in the Lowick and 

 Scremerston areas. 



* Some writers regard the Three Yards Limestone as a soutV^ern representative of 

 thD Six Yards, There is no doubt as to the identity of the Six Yards and Acre. 



