-IXX- PB0CEEDIN6S OP THE GEOLOGICAL SOCIETY. 



I. Lias formation, including, 



1. Lower Lias. 



2. Middle Lias. 



3. Upper Lias. 



II. Dogger formation (Brown Jura). 



1. Lower Oolite. 



2. Bath group. 



III. Malm formation ("White Jura). 



1. Kelloway group. 



2. Oxford group. 



3. Kimmeridge group. 



4. Purbeck beds. 



The author has added three large tabular diagrams, in which 

 the different formations in the three countries under consideration 

 are paralleled, and the principal fossils of each are given, as well 

 as the various Ammonitiferous zones which have been hitherto 

 looked upon as chiefly characteristic. 



M. Auguste Dollfus has published an important Monograph on 

 the Kimmeridge Fauna of the Cap de la Heve, near Havre, a 

 locality described by M. d'Archiac as being most rich in the 

 organic remains of this deposit. He first shows that this forma- 

 tion, almost purely argillaceous in the north, becomes more calca- 

 reous towards the south, and that this lithological change is 

 accompanied by a corresponding change in its organic contents ; 

 that while Ostrea and similar types predominate in the northern 

 portion of the basin, the Cephalopods and Grasteropods become 

 more numerous as we approach the calcareous districts. 



After describing the beds in the neighbourhood of Havre, he 

 proceeds to compare them with those of other localities. Towards 

 Boulogne the beds become more argillaceous, but as we proceed to 

 the south of England, the formation becomes so entirely argilla- 

 ceous that it is no longer possible to distinguish the different 

 subdivisions, and throughout the Avhole series, Ostrea, Gryplicea, 

 a,nd other Lamellibranchiata are the predominant forms, Eurther 

 north, in the Speeton clay, the lower portion of which represents 

 the Kimmeridge beds, the only hitherto known fossils belong to 

 the Lamellibranchiata. 



He then extends his comparison to the Department of the Mouse, 

 S.E. from Havre. Here the beds become more calcareous, and offer 

 but few points of palaeontological comparison with those of Cap 

 de la Heve. M. Buvignier has pointed out about eighty species 

 of Lamellibranchiate bivalves, of which only nine are common to 

 the beds near Havre, while the Gasteropods become very abundant, 

 showing about fifty species, chiefly belonging to genera unknown 

 in the moi-e northern region. This preponderance of the Graste- 

 ropods increases still more to the S.E., towards the extreme limit 

 of the basin; the same thing occurs with the Cephalopods, while 

 the Lamellibranchiata remain the same. 



Another point of comparison occurs in the Departments of La 

 Charente and La Charente Inferieure. But laere we are no longer. 



