Reviews. 159 



published, and of the plans and views of the author in carrying 

 out his undertaking. 



Professor Beyrich soon recognised the insufficiency of the pre- 

 viously existing catalogues, or lists of names of the Molluscous 

 Fauna of the tertiary beds of North Germany, to enable the geo- 

 logist to establish a correct comparison between them and the fos- 

 sils of other countries. They were generally unaccompanied by 

 illustrations. Even the investigations of Philippi respecting the 

 tertiary shells of Cassel, Freden, Zuilkorst, and the neighbourhood 

 of Magdeburg, are not sufficiently comprehensive to enable the 

 geologist to institute exact comparisons between them and the 

 productions of other localities ; the progress of the study of the 

 North German tertiaries has consequently been slow. The evil of 

 such an imperfect state of the literature of this branch of science 

 had been acknowledged by the Direction of the Imperial Institute 

 of Geology of Vienna, who immediately prepared the commence- 

 ment of a separate work on the shells of the tertiary basin of 

 Vienna by Professor Homes, in which not only the names but full 

 descriptions and accurate drawings of all known existing species 

 should be given. 



Professor Beyrich wishes to do for the North of Germany what 

 Homes has undertaken with regard to the Vienna basin. 



" It is my intention," he observes, " to extend the work to all 

 the tertiary formations which have been discovered, from the fron- 

 tiers of Belgium and Holland, eastward through North Germany 

 as far as the Oder. All these formations belong undoubtedly to 

 one series of deposits, closely connected with each other, and of 

 which the faunae are so intimately allied by numerous gradations, 

 that the removal of any single member from the series would 

 destroy the continuity of the whole. In order to have a clear 

 insight into the relative connexions of deposits which occur at such 

 various and distant points, we must bring together for comparison 

 the fossils from the neighbourhood of Dusseldorf, Osnahriick and 

 Biinde, those of Hildesheim and Cassel, those from Liineburg and 

 the island Sylt, as well as from the neighbourhood of Magdeburg, 

 and from the Markgraviate of Brandenburg. We must also exa- 

 mine the tertiary shells which have been transported into new posi- 

 tions in the diluvial deposits, in order to obtain a perfect view of 

 the molluscous fauna of the tertiary seas of the north of Germany." 



The eastern boundary of the country which Professor Beyrich 

 proposes to examine is somewhat artificial, being limited by the 

 extent of our knowledge on the subject. Between the Elbe and 

 the Oder, great progress has been made of late years in the inves- 

 tigations of tertiary geology, while no observations have been made 

 respecting the extension of these fossiliferous tertiary beds beyond 

 the Oder. The author thinks it probable, however, that they 

 nevertheless exist. The geological features of the country form 



