﻿Vol. 64.] THE FOSSILIFEEOUS SILURIAN EOCKS OF TORTWOETH. 537 



Ludlow. 



The question of the occurrence of true Ludlow Beds has been 

 discussed in the foregoing pages from field-evidence and from, strati- 

 graphical considerations. The palseontological evidence is slight, but 

 suggestive. The strongest and most direct indications come from 

 the calcareous sandstone full of lamellibranchs in one. of the trenches 

 south of Little Daniel's Wood. Here the whole faunistic stamp is 

 undoubtedly higher than that of the Wenlock, and all the lamelli- 

 branchs are Ludlow forms, though some range down. The other 

 fossils support this conclusion. 



The presence of Aviculopecten Danbyi in sand}?^ beds near Horseshoe 

 Farm is strong evidence of the presence of Ludlow deposits, for this 

 species is typically an Upper Ludlow one, and apparently has not 

 been found below that horizon. However, only the one specimen of 

 it in Lord Ducie's collection has come under our notice, and the 

 fossils with which it is associated in the same locality include 

 several which are not known from so high an horizon — Rhynchotreta 

 cuneata, RTiyncliospira Baylei, Orthoihetes 'pecten, Sirophonella funi- 

 culata, Orthis rustica, Triplecia Scdteri, Scenidium Leiuisi, none of 

 these heing recorded above the Wenlock. It is possible that all the 

 fossils from this locality are not from precisely the same strati- 

 graphical horizon, and the different lithological characters of the 

 rocks in which they occur point the same way. 



General. 



No new species have been detected among the collections of 

 Silurian fossils from the Tortworth area ; but, in many cases, the 

 material has been too imperfect to permit of more than the 

 determination of the genus. It is also obvious that the British 

 Wenlock species of corals require revision, and there is much work 

 to be done on the lamellibranchs as well. 



VI. Summary and Conclusions. 



(1) Certain corrections are made in the mapping, Wenlock beds 



for example being shown to occur in the Stone and Tort- 

 worth areas, and Llandovery in that of Eastwood. 



(2) Previous statements as to the thinness and imperfect develop- 



ment of the Ludlow rocks and as to the probable exposure 

 of the district to erosion in Ludlow and Lower Old-Eed- 

 Sandstone times are confirmed. 



(3) The igneous episode is shown to have been confined to the 



Llandovery. 



(4) The number of recorded fossils has been largely augmented. 



We cannot conclude without expressing our very great indebted- 

 ness to the Earl of Ducie, who has taken much interest in our work 

 and has assisted it in every possible way. We wish also to express 

 our most sincere thanks to Prof. C. Lloyd Morgan, E.K.S., and to 

 Dr. A. Vanghan for help and suggestions. 



