and the Palaozoic System of EnglamA. 309 



this evidence cannot be taken by itself. It it be called doubtful, 

 there is other evidence in reserve which is not doubtful, andwhich, 

 I think, proves that this Norbury group is an integral part of 

 the May Hill sandstone; that it is unconformable to the Cam- 

 brian rocks where the sections are most complete ; and that it 

 does form a portion of those important arenaceous and shelly 

 deposits which are, both physically and palseontologically, the 

 true base of all the overlying Silurian groups*. 



III. Sections of Horderley and the Onny. 



We were well aware of the importance of some sections at the 

 northern end of the Longmynd range, and it was part of our 

 plan to visit them. But my health gave way, and Prof. M^Coy 

 was unwilling to leave me ; we therefore removed to the neigh- 

 bourhood of the Onny, and he proceeded to examine the 

 sections above Stretford Bridge. Comparatively little could 

 have been made of them during a period of great inundation, 

 had not our friend Mr. Duppa previously made his promised 

 excavations in one or two places above the water-level, and con- 

 ducted Prof. M'Coy to them. The evidence was as follows : — 

 About 200 yards above Stretford Bridge, in an excavation 

 made where I had supposed (from my Notes of 1842) that the 

 Caradoc shale extended, they found many Wenlock fossils un- 

 mixed with any older types. Prof. M^Coy^s notes are as follows : — 



"1. In this excavation was an ahundance of the following 

 species : — 



Graptolites Ludensis. Calymene tuberculosa, 



Odontochile longicaudata. Cardiola interrupta. 



2. " Between this locality and that which follows, is a change 

 of surface ; and no rock, as stated to me by Mr. Duppa, is di- 

 stinctly seen for some hundred yards. This is the place where 

 we might expect to see the May Hill sandstone and the Penta- 

 merus (or Norbury) limestone ; but they are lost in the obscurity 

 of the section. 



3. " About 200 or 300 yards above Longville Bridge the 

 following fossils are abundant, without any intermixture of the 

 above-named Wenlock species : — 



Orthis calligramma. Leptcena sericea. 



elegantula (var. a). quinquecostata, 



parva. 



(All the above are Cambrian.) 



Spirigerina reticularis (Caradoc to Devonian inclusive). 



4. " About thirty yards higher up the river an excavation had 



* The reader will observe that all the groups below the May Hill sandr 

 stone are in this paper considered as Cambrian. 



