166 



L. Dudley Stainjo — Limit between 



of the Temeside shales of Shropshire. The discovery of marine 

 fossils in the latter has shown the folly of identifying this type of 

 lithology exclusively with lacustrine conditions. 



The Gedinnian has a similar facies to the south of Pepinster. 



(c) The Meuse Valley, south of Givet. 

 Here some splendid sections show the Poudingue de Fepin — a 

 thick, though local, conglomeratic base of the Arkose de Haybes — 

 resting on the upturned and eroded beds of the Cambrian. The 

 Arkose is succeeded by the Schistes de Mondrepuits (which are not 

 here very fossiliferous) and then by the Upper Gredinnian. 



{d) Mondrepuits and Macquenoise. 

 Here occur the most fossiliferous exposures of the Lower Gedinnian 

 (Schistes de Mondrepuits). The most abundant fossil is Rhynchonella 

 nucula, again the small form of the top of our Chonetes Beds. Other 

 characteristic fossils include Pterincea retroflexa, Bellerophon trilobatus, 

 Spirifer sulcatus, and Orthis jyersonata (Zeiler), the latter (well- 

 known from the Coblentzian) indicating clearly the affinities of the 

 fauna with the succeeding Devonian. 



B. The North of France (Pas-de-Calais). 

 During the German occupation of Lille, Professor C. Barrois, 

 Dr. P. Pruvost, and M. G. Dubois employed the leisure of their 

 forced confinement in the city in studying a large series of specimens 

 of Silurian and Devonian rocks from shafts and borings round 

 Lievin, Lens, Bethune, etc. A complete series of transition rocks 

 from the Silurian (Aymestry horizon) to the Devonian occurs in 

 this region, thrust over the Pas-de-Calais Coalfield. Results of very 

 great interest and importance have resulted from this study, of 

 which, apart from previous descriptions of a small part of the 

 fauna,' only a short resume has yet been pubHshed.'^ 



1 am deeply indebted to Professor Barrois and Dr. Pruvost, who 

 have allowed me to examine the specimens at the University of 

 Lille. 



The succession established is as follows : — 



Thickness in metres. 

 rSchistes et gres rouges et verts de 



I Vimy about 200 



"I Schistes et gres rouges et verts de 

 [_ Pernes 



{Psammites de Lievin . 

 Schistes de Mericourt . 

 Arkose de Bois-Bernard 

 (Grauwacke de Drocourt 

 Calcaire d 'Angres 

 Calcaire de Lievin 



^ Gosselet, Barrois, Leriche, & Crepin, " Description de la Faune siluro- 

 devonienne de Lievin " : Mem. Soc. geoL du Nord, vol. vi (ii), 1912. Leriche, 

 Mem. Soc. geol. du Nord, vol. v, 1906. 



2 C.R. des Seances de I'Acad. des Sci. (Inst, de France), vol. 167, 1918, p. 705. 



Gedinnien superieur 



Gedinnien inferieur 



Gothlandien superieur 



about 200 

 about 80 

 23 

 0-6 

 22 

 62 

 12 



