Vol. 68.] SUCCESSION- IN THE NORTH-WEST 0¥ ENGLAND. 461 



Geographical distribution. — The full deyelopment of this 

 sub-zone occurs only in the Shap and Eavenstonedale Districts. 

 The upper portion is present at Meathop, and probably also on the 

 western side of the Kendal outlier, and in the Purness District; 

 but it is absent from the Pennine area, which AYas not submerged 

 until a later period. 



(al) The Vaughania-cleistoporoides Band. 



This band consists of a yellow earthy dolomite a few feet thick, 

 passing into more shaly beds above and below. It occurs about 

 20 or 30 feet above the base of the zone. 



Geographical distribution. — It has only been met with in 

 the Shap and Ravenstonedale Districts, and the index-fossil is 

 connned to this band. 



(a 2) The Camarotcecliia-proava Band. 



This band forms a well-marked horizon, about 80 to 100 feet above 

 the Basement Conglomerate, in the Shap and liavenstonedale 

 Districts. The band reaches its greatest thickness in Eaveustone- 

 dale, and is characterized by the development of porcellanous 

 magnesian limestones. It thins rapidly north-westwards, and 

 disappears to the north of Shap. The fauna is scanty : it includes 

 Solenopora, Syringopora cf. reticulata, Seminula aff, ficoides, and a 

 large form of lUnjncJiotreta angidata. 



Geographical distribution.— At the summit of the Abbey 

 Cliff, Shap District. In Stone Gill, Piper Hole, etc. in the 

 Ilavenstonedale District. At Low Meathop in the jirnside 

 District. Below Cunswick Scar in the Kendal District. Un- 

 known in the Grange, Purness, and Pennine Districts. 



(h) The Seminula-gregaria Sub-zone. 



This sub-zone is comparatively thin. It includes the beds- 

 from the top of the porcellanous Soleno2:)ora series to the base of 

 the Michelinia Zone. The index-fossil is shown in PI. LI, fig. 5. 

 It occurs in many of the layers, and is associated with a form 

 resembling >S'. ficoides Yaughan. The base of the sub-zone is 

 marked by the characteristic Algal Band. 



Lithology. — In the Shap District the beds in the lower portion 

 are compact and dolomitic, usually purple v\'hen freshly broken, 

 abounding in drusy cavities, and often weathering to a dun colour. 

 In the south of the district and in Ilavenstonedale these beds take 

 on a more shaly character ; but in the upper portion of the 

 sub-zone the beds become more calcareous, and are specially 

 characterized by the development of oolites which are typical of 

 this horizon in the North- Western Province. Associated with this 

 oolitic development we frequently find an abundance of white 

 quartz-pebbles, which are distributed over a wide area in the 



