218 



On the Rhmtic or Avicula Contorta Beds rti Garden Cliff, Wesibury-upon- 

 Severn, Gloucestershire. By Robert Etheridge, F.G.S., F.R.S.E., 

 Palceontologist to the Geological Survey of Great Britain, and Honorary 

 Member of the Cotteswold Naturalists' Club, d'c, <kc. 



Bead at Gloucester, March 29tu, 1865. 



The great interest which has of late been created in the minds, both of 

 Continental and Biitish Geologists, relative to the Rhsetic series as a 

 group, and its relation to the two formations above and below, induces 

 me to give to the Cotteswold Club a brief description of tliese important 

 and remarkable beds, so well exhibited in many parts of Gloucestersliire 

 and the West of Englaiid, but especially so at Garden Cliff, Westbury- 

 upon-Severn, a well-known headland, two miles east of Newnham, and 

 on the northern side or bank of the river. 



It is well-known to most Geologists that the beds of shale, sandstone, 

 and marls, composing the structure of this fine section, and which form 

 the subject of this communication, have been regarded and described as 

 constituting a part of the Lower Lias series, in fact, the base of this 

 argillaceous group so finely developed in the valley of the Severn. 



Since the year 1828, when Von Buch" first under the name of 

 ©ewellien *Sct;icl;t, &c., drew attention to the peculiar assemblage of fossils, 

 or Palseontological features of the Rhaetic Group, up to the present day; 

 many and valuable papers have appeared, both from the pens of our own 

 countrymen, and from distinguished foreign Geologists. Numerous, also, 

 have been the terms applied to this series of deposits, now recognised 

 through Europe for their importance, and doubts still seem to be enter- 

 tained as to what name sliall be given to them in this country. As a 

 British equivalent, the term "Peuarth Beds" has been resolved upon 

 by the Geological Survey of Great Britaui ; mainly, we believe, from 

 the fact, that the beds of this age are finely exhibited in the headland 

 bearing this name, at the western promontory of Cardifl' Roads j and, 

 also, because it holds, or possesses, a distinctive appellation, — there being 

 many Westburys in the kingdom, but only one Penarth. 



* 93on 93ucl^, (2cljirt)t mit ©ciiH-Hien auf bcv ©niter 511^ nn (se^ticrge in t'cr 

 tai^r. 5ltpen, 5)eutfcf;r afab. ®iffenfc(). aVvIin, jatirg. 1828. 



