82 Mr.De laBeche on the Geographical Distribution of Organic 



!M. EJie de Beaumont has already remarked on the con- 

 stanc}' of the geological facts observable in the oolitic belt 

 of the great geological basin which contains London and 

 Paris*; — and M. Dufrenoyf has shown that in the South of 

 France appearances are not very materially different. There- 

 fore we may conclude that, though there may be many sub- 

 ordinate differences, there is a general resemblance in the 

 mass of the oolite series in England and a large part of France, 

 leading to the supposition that the rocks of which it is com- 

 posed were formed under similar general circumstances. 



It would appear that the three systems into which Mr. 

 Conybeare:]: has divided the oolite series of England, will be 

 available in the parts of France comprehended within this 

 sketch; therefore, in treating of the organic remains, we shall 

 first consider the lower oolitic system, then the middle, and 

 afterwards the upper. 



As data whence to draw conclusions respecting the geo- 

 graphical distribution of the organic remains in the rocks 

 under consideration, I shall avail myself, for the North of 

 England, of the very excellent work of Mr. Phillips §. For the 

 South of England I shall be compelled to use scattered in- 

 formation, as we have not any very detailed and published 

 description of the organic remains contained in the oolite of 

 this part of our island i|. For Normandy I shall have recourse 

 to M. de Caumont's work on Calvados^. For the North of 

 France, to the memoir of M. Boblaye **. And for the South 

 of the same country, to the observations of M. Dufrenoyf f. 



In order that the reader may judge of the general character 

 of the oolite series of which the fossils will be noticed in the 

 sequel, I have brought together the views of the geologists 

 above named respecting the different portions of which they 

 have particularly treated. 



•Note surl'iiniformite qui regne dans la constitution de la ceinture Juras- 

 sique du grand basin geologique qui comprend Londres et Paris. — Annales 

 des Sciences Naturelles, Juillet 1829. f Annales des Mines. 1829. 



J Outlines of the Geology of England and Wales. 



§ Illustrations of the Geology of Yorkshire. 



II The lists of organic remains of the oolite contained in the well known 

 " Outlines," &c. of Conybeare and Phillips, are much too general to be of 

 service in inquiries of the present kind; but when local information could 

 not be obtained, I have employed them for the midland and South of Eng- 

 land, which principally afforded the materials for their construction. 



^ Essai sur la Topographic Geognostique du departement du Calvados. 

 Caen 1828. 



** Memoire sur la formation Jurassique dans le Nord de la France. — 

 Ann. des Sci. Naturelles. Mai 1829. 



"t-f Des formations secondaires qui s'appuient sur les pentes meridionales 

 des montagnes anciennes du centre de la France. — Part entitled " Forma- 

 tions Jurassiques du Sud-ouest de la Yvance". — Annales des Mines, torn. v. 

 1829. 



General 



