Vol. 62.] THE HIGHEST SILURIAN OF THE LUDLOW DISTRICT. 195 



10. The Highest Silurian Rocks of the Ludlow District. By 

 Miss Gertrude L. Elles, D.Sc (Dublin), and Miss I. L. 

 Slater, B.A. (Dublin), Newnham College, Cambridge. (Com- 

 municated by Prof. T. McKeioty Hughes, M.A., F.R.S., F.G.S. 

 Read December 20th, 1905.) 



[Plate XXII— Map.] 



Contexts. 



Pace 



I. Introduction and Bibliography 1D5 



II. Classification 197 



III. Tectonics 200 



IV. Scenery 201 



V. Detailed Description of the Beds 201 



VI. Conclusions 218 



VII. Fossil Lists 211* 



I. Introduction and Bibliography. 



The Ludlow district has been regarded as classic ground since 

 the days of Murchison, and, although it has been much neglected 

 by the geologists of more recent times, local collectors of fossils 

 have placed in the Ludlow Museum a collection which is probably 

 unsurpassed for its excellence in illustrating the geology of the 

 neighbourhood. 



Many papers were written upon the district by Murchison and 

 others of his time ; but, with the exception of Miss Wood's paper 

 on the Lower Ludlow Shales, 1 there has been no revision of its 

 geology since their day: and we are of opinion that the area 

 presents many features of interest, both structurally and otherwise, 

 which can only be brought out by more recent methods of research. 



The more important papers dealing with the district are the 

 folio wins: : — 



Murchisox, 1834. 



Proc. Geol. Soc. vol. ii, 



p. 12. 



The earliest definite mention of the rocks of the Ludlow 



district appears to be found in a paper published 



by Murchison in 1834. In this he gives the name 



Ludlow to the beds at the top of the 'Grauwacke 



Series,' and groups together all the passage-beds into 



the Old Red Sandstone under the name of ' Tilestones,' 



which he regards as the lowest division of that Series. 



Muechisox, 1839. In the 'Silurian System' he gives a few more details 



' Silurian System ' respecting these passage-beds, and refers the lower 



pp. 196 et seqq. members of them to the Silurian System, under the 



name of Downton-Castle Building-stone; he 



also notes the more important localities where they 



may be studied, and records the discovery of the Bone- 



Muechison, 1853. Bed in the Upper Ludlow Beds by the Rev. T. T. Lewis 



Quart. Journ. Geol. Soc. j and Dr. Lloyd, the fossil-contents of this bed being 



vol. ix, p. 16. described by him in a subsequent paper. 



1 Quart. Journ. Ge..l. Soc. vol. lvi (19U0) p. 415. 



