102 



PMOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



worked for buildiiig-stone, they are above 40 feet, and, at some spots 

 near Clermont mentioned by M. Graves, 46 feet thick*, Proceedino- 

 still westward in the direction of Normandy this division decreases 

 in thickness. M. Graves gives no separate measurements of it, but 

 he states that at St. Cyr-sur-Chars the thickness of the '* Groupe 

 calcaire" (in which are included this and the next division) does not 

 exceed 25 to 32 feet ; whilst at the western escarpment of the French 

 tertiaries the thickness of these strata varies from 6 to 16 feet only. 

 It is in this part of the Calcaire grossier that the rich shell-beds 

 of Grignon, Damery, and Courtagnon occur. The fauna includes 

 many hundred species ; but again, confining ourselves to the lists of 

 the more abundant and common species mentioned by M. Graves 

 from Hermes, Mouchy-le-Chatel, Ully-St. -Georges, Amblainville, 

 Parnes, Chaumont, &c., which only amount to about 1 20, I find that 

 of that number the following 5/ range to Bracklesham, besides the 

 larger proportion of those enumerated above in the first or lower 

 division. In the same v>^ay, many of the following are found in the 

 lower division. These lists are merely intended to show those spe- 

 cies which, according to M. Graves's numerous local details, are the 

 most common and typical in the two zones. As it cannot however 

 be said that any species are distinctly peculiar to the lower division, 

 T have taken the first and second divisions together in the general 

 list at p. 93-97. 



Belosepia sepioidea. 

 Bifrontia bifrons. 



disjuncta. 



marginata. 



Caneellaria costulata« 

 Cerithium giganteum. 

 Conus antediluvianus ? 

 CyprfEa inflata. 

 Delphinula Warnii. 

 Fusus longsevus. 



Noffi. 



-^ rugosus. 



Marginella eburnea. 



ovulata. 



Melania costellata. 

 Murex tricarinatus. 

 Natica depressa. 



sphserica. 



Willemettii. 



Parmophorus elongatus, 

 Pileopsis squamseformis. 

 Pleurotoma dentata. 



granulata. 



■ prisca. 



trans versaria, 



Pyrula nexilis. 

 Rissoa cochlearella. 

 Rostellaria macroptera. 

 Scalaria tenuilamella. 



Sigaretus eanaliculatus. 

 Solarium canaliculatum. 



patulum. 



Tornatella sulcata. 

 Tmritella carinifera. 



sulcata. 



— — multisulcata, 

 Voluta cithara. 



muricina. 



spinosa. 



Area interrupta- 

 Cardium hippopseum, 

 Chama gigas. 

 Corbula gallica. 



rugosa. 



Crassatella compressa. 

 Cytherea nitidula. 



semisulcata. 



sulcataria. 



Nucula margaritacea. 



ovata. 



striata. 



Ostrea elegans. 

 Pecten plebeius. 

 Pectunculus pulvinatus. 

 Solen parisiensis. 

 Tellina scalaroides. 

 Venericardia imbricata. 



* M. D'Archiac mentions in one place 60 to 65 feet ; p. 590 



