Paleontology. 329 



black slaty rock, is surinounted by a bed of fissile argillaceous 

 limestone containing belemnites, and this last passes insensibly 

 into a black slaty clay, containing impressions of plants identi- 

 cal in species with some of those belonging to the true coal 

 formation. M. de Beaumont concludes his detailed descrip- 

 tion in these words : — " II me parait done incontestable que le 

 sy steme de couches qui, k Petit-Coeur, contient les Belemnites 

 et les impressions vegetables, et qui s'enfonce sous toutes les 

 autres couches non-primitives de cette partie des Alpes, appar- 

 tient d la formation du liasy The plants were carefully ex- 

 amined by M. Adolphe Brongniart, and in an accompanying 

 memoir, descriptive of them, he states, '* que I'identite le plus 

 parfaite existe entre ces plantes et celles du terrain houiller, 

 tandis qu'il n''y a aucun rapport entre elles et celles qui se 

 trouvent habituellement dans le lias, ou dans les terrains 

 oolitiques.'' He enumerates among others of Petit-Coeur, 

 Neuropieris tenuifolia, found at Liege and Newcastle; and 

 Pecopteris polymorpha, one of the most common in the coal- 

 fields of France. 



At the meeting of the Geological Society of France at Cham- 

 bery in autumn 1844, an account of which we have received 

 since our last Anniversary,* the attention of the members was 

 directed to this most remarkable fact, in a memoir by M. 

 Rozet ; and afterwards, several who attended the meeting 

 visited Petit-Coeur. The observations of M. Elie de Beau- 

 mont and M. Adolphe Brongniart were confirmed in every 

 particular; they found abundance of the vegetable remains, 

 and of belemnites below them. The report farther states: — 

 " II a ete evident aussi, pour tous les membres de la Societe, 

 que Ton ne pent aucunement admettre I'explication d'un plis- 

 sement qui aurait raproche les fossiles de deux formations et 

 produit une alternance apparente entre les couches a Belem- 

 nites et les couches a empreintes. Ce sont les memos schistes 

 et la meme formation qui renferment ces deux genres de fossiles 

 que Ton avait cru pendant longtemps appartenir a des epoques 

 geologiques tres eloignees I'une de I'autre." M. Sismonda, who 

 was present, stated, that in another locality he had found 



* Bulletin de la Soc. Gcol. de France, vol. i., new series, p. 601. 



