102 M. B. de Basterot's Observations on Fossil Shells. 



on the N. of the Teutoburgerwald. The Wichengebirge is 

 composed of keuper, lias, and the marl and sandstone of the 

 lias, which rest on muschelkalk. In the lower part of the 

 lias marls there are many coal beds, running E. and W., 

 and dipping N. The principal bed is two feet thick. Many 

 coal beds are found above the principal bed at Trotheim and 

 Tappenstadt. 



6. Observations on Fossil Shells; by M. B. de Basterot*. 



The geographical distribution of organized beings over 

 the surface of the globe, has long since furnished a subject 

 for the meditation of the naturalist. The limits of regions 

 occupied by different families of quadrupeds, oviparous ani- 

 mals and plants, have been pointed out in a series of ingenious 

 observations. The animals of a less elevated order have not 

 been observed, in this point of view, with the same attention. 

 The molluscous animals, so very abundant, so interesting by 

 the variety, the beauty, and the number of the fossil remains 

 which they have left on our continents, have been entii'ely 

 neglected in this respect. Let us in imagination transport a 

 naturalist on an unknown shore, covered with the remains of 

 arborescent ferns, palms, gigantic Graminca:, the bones of 

 elephants, tigers, hyaenas, &c. ; would he not immediately re- 

 cognize the productions of the torrid zone ? But let this coast 

 be alone covered by the productions of the sea, by molluscous 

 and zoophytic animals ; woidd they reveal to him the climate 

 in which he was placed? I should think not; for though the 

 frequency of univalves may have been remarked between the 

 tropics, as among fossils, we are far from possessing general 

 and certain knowledge on this subject. 



I would wish to fill up this blank, and endeavour to sketch 

 the geogi'aphical distribution of ^eMollusca, but the time does 

 not appear to be yet arrived. " Let us not forget," says 

 M. Decandolie, speaking of botanical geography, " that this 

 science can only commence when the study of species has be- 



respecting the Brora coal-field (an abstract of which appears in the Phil. Mag. 

 for March), and which he considers equivalent to the coal of the Eastern 

 Moorlands of Yorkshire. It may not be improbable that the coal of Teck- 

 lenburg-Lingen is the equivalent of the Brora and Yorkshire coal ; for the 

 oolitic scries is not in general well understood in Germany, and much con- 

 fusion seems to exist respecting the equivalents of muschelkalk, quader- 

 sandstein, keuper, Sec. Be this as it may, the fart contained in the text is 

 important ; as it presents us with another instance of a useful carbonaceous 

 deposit being found in the oolite formation. — Traiu. 



* Extracted from the author's Manoire Gcologique sur Ics Enmrons dc 

 Rordcaiu, inserted in the Mnn, dc la Sue. d'llislvirc Nal.dc Paris, vol. ii. 



come 



