20 



PllOCEEDINGS OE THE GEOLOaiCAL SOCIETY. [N"oV. 21 



covered with sulphide of iron. The surface is much worn and per- 

 forated, and is covered by alternations of clays and marls, which 

 lie unconformably on it, and contain Gryplicea incurva, Nautilus 

 striatus, and Limaglgantea. It will be noticed that Septrastrcea execi- 

 vata, one of the Brocastle Madreporaria, is grouped in Normandy 

 with the Gasteropoda which are associated with the coral-fauna of 

 the Brocastle beds. The Thecosmilia mentioned above has its repre- 

 sentative species at Brocastle, and probably at Cowbridge. The 

 Calcaire de Yalogne has the homotaxis of Brocastle to a certain 

 extent. 



In the Department of the Cote d'Or*, the highest member of the 

 Infra-Lias differs lithologically from the Gryphaea-limestone above 

 it ; this Foie de Yeau, or the zone of Ammonites Moreanus, lying 

 beneath the Gryphasa-limestone, has a varied raineralogical com- 

 position. In some places there are calcareous marls with grains of 

 quartz, or black marls, schistose and brittle, and compact nodular 

 limestone. The yellow marls of the zone are generally unfossili- 

 ferous ; but the blue argillaceous limestone contains many fossils, 

 which weather out of a yellow colour. The following species of 

 Madreporaria are found in the Foie de Yeau : — 



Montlivaltia Sinemuriensis, d^ Orb. 



• Martini, de From. 



Thecosmilia Martini, de From. 

 Septastrcea excavata, de From. 



Isastr£ea Sinemuriensis, de From. 

 Stylastraea Sinemm-iensis, de From. 



Martini, de From. 



Astrocgenia Sinemuriensis, d'Orb., sp. 



The following section at Yic de Chassenay refers to the upper 

 part of the Infra-Lias or the Eoie de Yeau : — 



Calcaire a Gryphees arquees. 

 Yellow marls without fossils. 



Blue argillaceous limestone 



Yellow unfossiliferous marls, 



Blue-grey argillaceous limestone . . . - 



IJnfossiliferous marl. 



Littorina clathrata, Desk. 

 Turritella Dunkeri, BimJc., sp. 



Deshayesi, Tqin. 



Pleurotomaria Anglica, Sow. 

 Cardinia sublamellosa, d' Orb. 

 Lima gigantea {var. edule), d' Orb. ' 

 Pecten Valoniensis, de Fr. 

 \ Montlivaltia Sinemuriensis. 



Ammonites Moreanus, d' Orb. 

 Littorina clathrata, Besh. 

 Turritella Deshayesi, Tqm. 

 Cerithium Semele, i)' Orb. 



gratum, Tqm, 



acuticostatum, Tqm. 



Thecosmilia Martini, de From. 

 Stylastr^a Sinemuriensis, de From, 

 — — Martini, de From. 

 ^ Astroc£enia Sinemuriensis, i/(?r5,, sp. 



* Maytin, Pal. strat. de I'Infra-lias, &c., 1800. 



