8 TEILOBITES FE03I THE DTPEE GKEEN SLATES OP NORTH WALES. 



J. W. Salter and H. Hieks, 1869. Quart. Journ. Geol. Soc. 



vol. XXV. p. 51, pis. ii. & iii. 

 Henry Hicks, 1871. Quart. Journ. Geol. Soc. vol. xxvii. p. 399, 



pis. XV. & xvi. 

 Henry Hicks, 1872. Quart. Journ. Geol. Soc. vol. xxviii. p. 173, 



pis. v.-viii. 

 J. W. Salter and R. Etheridge. Mem. Geol. Survey. "The 



Geology of jN'orth Wales," by A. C. Ramsay. Appendix on 



Fossils. 2nd edition, 1881. (26 plates.) London, 8vo. 



EXPLANATION OF PLATE IV. 



Fig. 1. ConocorypTie Viola, H. Woodw. Nat. size. 



Longmj^nd Grroup, Penrhyn Quarries, Bethesda, near Bangor. 



2. Detached head of same species, squeezed obliquely by slaty cleavage 



(nat. size), from same locality and formation. 



3. Restoration of fig. 1, by the author. 



(The originals of figs. 1 and 2 are in the possession of Prof. James J. Debbie, 

 University College of North Wales, Bangor. ) 



Discussioi^. 



The President rejoiced that the charge of barrenness had been so 

 effectually removed from these rocks. 



Mr. Etheridge commented on the good work done by Dr. Hicks 

 and others amongst the Cambrian rocks of Wales. J^othing had 

 hitherto been found in the Bangor and Llanberis rocks. There was 

 some question at first whether the Trilobite was more allied to the 

 Olenidee or to the Conocephalidae. 



Dr. Hicks said the fossils, according to the section, occurred in 

 Lower Cambrian rocks, but the lowest fossiliferous horizon at St. 

 David's was yet older. The position seemed to be above the Llan- 

 beris Slates, but at the base of the Harlech-grit series. There 

 could be no reasonable doubt of the authenticity of the fossils. 



Dr. Woodward called attention to a diagram showing a restora- 

 tion of the fossil. 



