652 C. CALLAWAY ON A NEW AREA OF UPPER 



34. On a new Area of Upper Cambrian Bocks in South Shrop- 

 shire, with a Description of a new Fauna. By Charles 

 Callaway, Esq., M.A., B.Sc. Lond., F.G.S. (Bead March 21st, 



1877.) 



[Plate XXIV.] 



Introduction. 



In March 1874 I communicated to this Society a paper entitled, 

 " On a Tremadoc area near the Wrekin in South Shropshire, with 

 description of a new Fauna," which was published in abstract in 

 the Society's Journal, vol. xxx. p. 196. 



In that paper I described certain shales, commonly supposed to 

 be Caradoc, which I had examined at Shineton, two miles S.S.W. 

 of the Wrekin. In these shales I had found ConocorypJie, Linguletta, 

 and other fossils of a Cambrian * type ; and from this and other 

 evidence I had concluded the beds were of Tremadoc age. My views, 

 however, were not accepted by the Fellows present at the reading 

 of my paper, on account of the alleged imperfection of the fossil 

 evidence ; and, as I was at the time absent in America, I had no 

 opportunity of defending my position. Since my return home I 

 have collected more abundant and satisfactor3 r evidence, both geolo- 

 gical and palaeontological, which I venture to think will establish 

 my original conclusions. I have also made out some additional 

 points of interest in the geology of the neighbourhood of the 

 Wrekin. 



Previous Information. 



Sir B. Murchison has described the area under examination, from 

 the Wrekin on the north-east to the May-Hill Sandstone at Kenley 

 on the south-west, as composed of strata of Caradoc age, the 

 Wrekin itself being an igneous outburst altering the Caradoc sand- 

 stone on its flanks into quartzite. 



The Geological Survey has followed Murchison, but has included, 

 under the name of " quartzite," certain sandstones in which I have 

 detected fossils in abundance. 



In the Journal of this Society (vol. x. p. 62), Messrs. Aveline 

 and Salter describe this area as Caradoc, and Salter gives a list of 

 fossils from (so-called) Lower Caradoc shales at Harnage and 

 Shineton, mixing up Cambrian forms, such as Olenus, from Shine- 

 ton, with Cambro- Silurian genera, such as Trinuclens, from Harnage, 

 the shales at Shineton and at Harnage evidently being considered 

 identical. 



* I adopt Mr. Hicks's classification of the Cambrian rocks, and the name 

 " Cambro-Silurian " for the groups from the Arenig to the Lower Llandovery 



inclusive. 



