438 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 22, 



The corals are — 



*Limaria fruticosa, Steing. Cyathophyllum dianthus, Goldf. 



clathrata, Steing. turbinatum, Goldf. 



*Porites tubulata, Lonsdale. *Turbiao]opsis bina, Lonsdale. 



pyriformis ?, Lonsdale. Favosites Gothlandica, Lamk.-\ 



In addition to these, there are at AYoodside fragments of gigantic 

 Crinoidea of indeterminate genera. 



The Limaria is so abundant at Nash, that it is evident the existence 

 of the calcareous formation is due to that coral. None of the shells 

 occur in abundance. At the time of the publication of the ' Silurian 

 System,' only one specimen of the Pentamerus Knightii, Sow., had 

 been observed ; since that period three or four specimens have been 

 obtained. 



In the thin band of limestone at the Sandbanks I have found — 



Orthis pecten ?, Dahn. Orbicula Forbesii, Davidson. 



Lingula quadrata ?, Eichw. 



It is a remarkable fact that not a single specimen of the Pentame- 

 rus Icevis, Sow., which is a most abundant fossil in the Caradoc sand- 

 stone of this district, has been met ■\;^ith in the hmestone or shale. 

 Atrypa hemisphcBrica, Sow., is the only characteristic fossil of the 

 lower beds of sandstone that has found its way mto the overlying 

 shale, and the specimens of it in the latter are very rare. 



If the question were merely, whether the Nash limestone was re- 

 ferable to the Upper or Lower Silurian system, it would scarcely admit 

 of argument. Terehratula crispata, Sow., Orthis rustica. Sow., O. 

 orbicularis, Sow., Spirifer trapezoidalis, Buch, Atrypa compressa. 

 Sow., A. linguifera. Sow., and Asaphus caudatus, Brong., to say 

 nothing of the LimajncB, not one of these fossils having ever been 

 found in Lower Silurian rocks, prove that the Nash hmestone is un- 

 doubtedly a member of the upper system ; and if the Woolhope lime- 

 stone were still to be ranked as the upper bed of the Caradoc sand- 

 stone, there would be an end of the question. Mr. PhiUips, how- 

 ever, in his elaborate and valuable memoir on the Malvern Hills J, 

 has laid it down as beyond dispute that the Woolhope limestone is 

 the lowest member of the Wenlock series ; and if the correctness of 

 this be admitted, the question now under consideration becomes one 

 of very great nicety, in the determination of which the evidence 

 derived from the actual position of the beds acquires greater weight, 

 while the variation in the organic contents must be necessarily of 

 a very limited extent. 



To the argument, however, derived from the position of the hme- 

 stone immediately above the sandstone, I answer, that the whole of 

 the Wenlock series is so thinned out at this spot as not to admit of 

 any separation into upper and lower beds, and that the hmestone and 

 shale maybe said to rise from beneath the Lower Ludlow rock§ with 



t In determining the species of the various fossils of the localities, I am in- 

 debted in a great measm-e to the kind assistance of Mr. D. Sharpe. 

 X Memoirs of the Geological Survey, vol. ii. pt. 1. pp. 74, 169. 

 § This is the precise expression used by Sir R. Murchison. 



