Yol. 68.] STJCCESSION- IN THE IfOETH-WEST OP ENGLIND. 499 



dolomite and mudstone are, however, exposed in Weasdale Beck, 

 along the same line of strike ; while below Shaw Mire in Thack- 

 thwaite Gill, shales, gritty mudstone, and dolomite are exposed : 

 these have, however, yielded no organic remains, and the same 

 remark applies to the lowest beds exposed in Artlegarth Beck. 



The Solenopora Sub-zone. — The fossiliferous beds overlying 

 rtbe basement Carboniferous conglomerate are best studied in the 

 series of gills which rise on the northern slopes of the Howgill 

 Pells between Pinskey Gill and the Dent Pault. The general 

 character of the succession is shown in the section (PL LYI, fig. 2). 

 The best exposures of the lower beds are seen in Stone Gill and 

 Artlegarth Beck. In Stoue Gill some 80 feet of dolomites and 

 calcareous shales crop out about a third of a mile above Colbeck 

 Bridge. Unfortunately the lowest beds, including the basement 

 conglomerate, are not exposed here. 



Section in Stone Gill. 



Thickness in feet inches. 

 Porcellanous limestone with Cariiarotoechia 2Jroava — 



~ Black shale 4 



Massive limestone with sbaly partings , 14 



Black shales with Orthoceras 4 



Hard, compact, grey limestones with geodes 3 6 



Black shales with plates of ArchcBocidaris 2 



Earthy limestone 1 



Shale-band 2 



Solenopora ^-Awdi 2 



Drift-coTered (unseen) 5 



Hard dolomite and shaly calcareous Hags 7 



Palcechinus Limestone, with Zaphrentis omaHusi and 



Cidaris spines ... 1 6 



Fragmental bed 4 



Shaly dolomite 7 6 



Dolomite with Vaughania deist oporoides 9 



Hard, dun-coloured, shaly limestone 6 



'^Vn.iy ^\i?i\e \y\i]i Athyr is glahristria, o%ivn.co^?,, etc 3 3 



Hard blue limestone with 8yringopora and Hyalostelicc . 3 



Base not seen. 



These beds represent approximately the same horizon as those 

 exposed in Shap- Abbey Cliff already described (p. 487). The beds, 

 as in the case of the Shap section, contain abundant remains of 

 8olenoj)ora : one layer, 45 feet from the base, being almost entirely 

 composed of the thalli of these organisms. The abundance of 

 Athyris glabristria in the lowest shale-bed, near the base of the 

 section, recalls a similar layer near the top of Shap- Abbey Cliff; 

 while the presence of a bed composed almost entirely of the plates 

 of Palcechinus and Archceocidaris corresponds with the Ai-chcEO- 

 cldaris Bed north of Keid. The interesting band containing 

 Vaughania cleistojooroides has only been met with elsewhere in the 

 Shap section, and there the coral-remains are very scarce and 

 fragmentary. The fauna from these beds is tabulated in the 

 general list on p. 460. 



2o2 



