506 PROF. H. A. NICHOLSON AND MR. J. E. MARR ON 



Trinucleus seticornis, His. 

 Orthoceras sp. 



No. 6 of the section consists of blue shales with Strophomena 

 siluriana, Dav., and the undermentioned fossils, all found in the 

 corresponding Ashgill shales of the Lake District : — 



PJiacop^ miicronatus, Brongn. (?). 

 OrtJiis biforata^ Schloth. 



elegantida^ Dalm. 



protensa, Sow. 



Orthisina sp. 



Stropliomena siluriana, Dav. 



Above the Ashgill Shales, a strike-fault cuts out the Skelgill 

 beds in the main stream, but they are found in the tributary 

 stream, Rundale Beck. These and the deposit 'No. 7 of our section 

 (the Browgill series) have been previously noticed in our paper 

 " On the Stockdale Shales," and we have nothing to add to the 

 description given therein. The Browgill beds pass up as usual into 

 the blue flags with Monograptus vomerinus (No. 8), which apper- 

 tain to the Lower Coniston (Brathay) Flags, and which represent 

 the Wenlock Shales of other areas. These, as shown in the map 

 and section, abut against the J^ew Eed Sandstone (No. 9) which is 

 thrown against them by the Pennine Eault just east of the village 

 of Knock. 



In continuing our description of the rocks it will be convenient 

 to consider the blocks into which the west side of the Inlier is 

 divided by the cross-faults. The block to the south of the one last 

 described is about two miles long, and is bounded on the south by 

 the Harthwaite Fault. It is occupied by a greatly disturbed syncline 

 having the rhyolites of Dufton Pike to the north-east, and those of 

 Wharleycroft with a thin band of andesite (the latter probably 

 the oldest rock seen in the western half of the Inlier) to the 

 south-west. Between these the moory country is mainly occupied 

 by the Dufton Shales, well exposed in Hurning Lane, Pusgill, 

 Dufton Town Sike, Billy's Beck, and Harthwaite Beck. That they 

 are much disturbed is shown, not only by the great crumpling which 

 they have undergone as seen in actual section, but by the occur- 

 rence of lenticular outliers of higher strata on the S.W. slope of 

 Dufton Pike, at Pusgill House, and near the head of Billy's Beck, 

 and of an inlier of lower deposits in Harthwaite Beck, against the 

 Harthwaite Fault. 



The principal point to be noticed concerning the rocks of this 

 block is the very fossiliferous character of the " (7o?-o»rt-beds " of 

 Pusgill, of the Dufton Shales of Pusgill, Dufton Town Sike, and 

 Billy's Beck, and of the StaurocepJialus Limestone near the head of 

 the latter, containing, amongst other fossils, Staurocephalus globicej^s, 

 Portl., and a new species of Sl-eaidium. 



South of the Harthwaite Fault is a triangular block apparently 

 extending to Murton, though no exposure has been seen by us in 



