ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxxi 



€at bodies, whether concave, convex, or flat, or any combination of 

 these forms, as well as the dimensions of irregularly formed bodies. 

 It is also applicable to the measurement of crystals and minute objects 

 of natural history, and to other purposes connected with the arts and 

 industrial pursuits. Even the thickness of a sheet of paper may be 

 ascertained by means of it. Dr. Sandberger has presented one of 

 these instruments to this Society, to which I have already had occasion 

 to direct your attention, and for which our best thanks are due to 

 him. 



During the past year Prof. Beyrich has published, in the * Journal 

 of the German Geological Society,' the third part of his work on the 

 shells of the tertiary formation of the North of Germany. The 

 genera described in this part are Tritonium=Triton, Lam., 7 species ; 

 Murex, 14 species ; Tiphys, 4 species ; Spirilla^ 1 species ; Leiostomay 

 1 species ; Pyrula, 6 species. It is impossible to overrate the import- 

 ance of this work, and when we consider the attentive care which 

 Prof. Beyrich has brought to bear on the task he has imposed on 

 himself, we are justified in looking forward to its completion as the 

 inauguration of a new epoch in our knowledge of the North German 

 Tertiaries and of their relations to those of Belgium, France, and Eng- 

 land. I have fully alluded to this question on a former occasion ; I 

 will therefore now merely recal to your attention the objects which 

 Prof. Beyrich had in view in undertaking this work. When he 

 first began to direct his attention to this subject, he soon perceived 

 the insufficiency and incorrectness of all the previously existing 

 catalogues or lists of names of the molluscous fauna of the tertiary 

 beds of North Germany, and how ill-adapted they were to enable 

 the geologist to establish a correct comparison between it and 

 the fossils of other countries. They were generally unaccompained 

 by illustrations. This evil had been already acknowledged by the 

 Imperial Geological Institute of Vienna, who had charged Dr. Homes 

 with the preparation of a separate work on the fossil shells of the 

 tertiary basin of Vienna, in which not only the names, but full descrip- 

 tions and accurate drawings of all the species should be given. What 

 Dr. Homes had undertaken for the Vienna basin, Prof. Beyrich pro- 

 poses to accomplish for the North of Germany. 



" It is my intention,'* observes Prof. Beyrich in the first part of this 

 work, " to extend my observations to all the tertiary formations which 

 have been discovered from the frontiers of Belgium and of Holland, 

 eastward through 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 faunas are so intimately allied by nume- 

 rous 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 compa- 

 rison the fossils from the neighbourhood of Diisseldorf, Osnabrllck, 

 and Biinde, those of Hildesheim and Cassel, those of Lllneburg and the 

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

 and from the Marches of Brandenburg. We must also examine the 



