AUSTEN ON THE EOULONNAIS. 241 



description. I noticed forms of Crinoids, and of bivalve, gasteropod, 

 and cephalopod shells such as occur in our Devonshire series ; with 

 these were also other forms, such as Tentaculites, Conularia, &c., and 

 which may possibly prove identical with those of the Cotentin. 



Terebratula conceiitrica. Leptsena latissima. 



reticularis. Productus subaculeatus. 



• hastata. scabriculus. 



— — pleurodon. Crania. 



Spirifer Bouchardi. Serpula omphalodes. 



■ calcaratus, Aulopora tubaeformis. 



disjunctus. Favosites polymorpha. 



protensus. spongites. 



subconicus. Astrasa ananas. 



Orthis resupinata. Cyathophyllum csespitosum. 



Strophomena senilis. hexagonum. 



opercularis. turbinatum. 



Leptsena Dutertrii. Calymene Latreillii. 



Dolomitic Limestone. 



A considerable thickness of red shales underlies the Fiennes and 

 Ferques limestone and separates it from a band of compact dolomitic 

 limestone, the harder portions of which may be seen projecting in 

 rude weathered masses, above the usually level surface of the lime- 

 stone district ; this band is fossiliferous, but as the rock is not quar- 

 ried, its contents are not easily ascertained. At the Boulogne Meet- 

 ing Sir R. Murchison pointed out its mineral resemblance to the 

 Dolomite of Gerolstein (Bull, de la Soc. Ge'ol. de Fr. t. x. Dolomie 

 Silurienne, p. 23). Its age or relative position is about the same. 



The eastern breadth of this band on the surface is about 50 yards ; 

 it is underlaid by a thick series of argillaceous shales. 



Blacourt Limestone. 



Though this band may be identified at several places, it is only on 

 the section S.W. from the farm of La Cedule, that the sequence of 

 the lower portion of the series can be satisfactorily made out. The 

 uppermost portion of this band consists of a rag-limestone, full of 

 branches of Favosites, with thin carbonaceous seams and calcareous 

 shales. The limestone strata beneath these are of considerable thick- 

 ness ; fossils are abundant in the partings of shale. This band has 

 been quarried on the line of section from La Cedule ; in a S.E. direc- 

 tion it crosses the road from Beaulieu to Les Communes, just where 

 another branches off towards Caffiers : in the contrary direction 

 it crosses the common land south of Landrethun, and is the lime- 

 stone which is reached in the workings for iron-ore N. and E. of 

 Blacourt. 



The fossils of this band are — 



Terebratula ambigua. Strophomena opercularis. 



pleurodon. Leptaena Dutertrii. 



reticularis. fragraria. 



concentrica. Favosites polymorpha. 



Spirifer Bouchardi. ■ spongites. 



disjunctus. Cyathophyllum turbinatum. 



Orthis resupinata. 



