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III. TRANSLATIONS AND NOTICES 



OP 



GEOLOGICAL MEMOIRS. 



I. On the muddy deposits at the Mouths and Deltas of various 

 rivers in Northern Europe, and the infusorial Animalcules 

 found in those deposits. By Christian Gottfried Ehrenberg. 



[From the Verhandl. der Konigl. Preuss, Ak. der Wissensehaften zu Berlin. 1843.] 



The Proceedings of the Royal Academy of Sciences at Berlin 

 have, during the last two years, contained many interesting notices 

 by M. Ehrenberg, on the extensive development of the skeletons 

 of microscopic animalcules as a constituent part of the rocks of 

 Central America and Western Asia. They are more or less 

 abundant in all the limestones and cretaceous formations of these 

 districts, as well as both in the Tripoli stones and blue marls of a 

 more recent period, and in the oolitic limestones of an older age. 



One of the most interesting results as regards geological in- 

 vestigations at which Professor Ehrenberg has arrived, is the cir- 

 cumstance of having discovered in the mud now deposited at the 

 mouths of large rivers, forms of microscopic life and infusoria 

 identical even in species with those found in the fossil state in the 

 oolitic and cretaceous formations in every quarter of the globe. 



Under these circumstances, we have thought it advisable to 

 give a somewhat elaborate abstract of M. Ehrenberg's researches 

 on this subject. 



On the 10th July, 1843, M. Ehrenberg read before the Roy. 

 Acad, of Sciences of Berlin a paper entitled " Observations on the 

 perceptible Influence of Microscopic Marine Organisation on the 

 Soil of the Bed of the Elbe above Hamburgh." 



The author in this paper states, that having already, in 1839, 

 remarked the influence of microscopic organic life on the marsh 

 lands of Cuxhaven, he continued his examination of the humus of 

 the marshes ; and amongst the numerous interesting results of 

 these inquiries, none can be more important than those by which 

 it appears that the microscopic animalcules of the Elbe, even at a 

 considerable distance from its mouth, and as high up as Hamburgh, 

 cannot be distinguished from those inhabiting the ocean. 



At the author's request, a friend at Gliickstadt had sent him in 

 the preceding year several specimens of earth and soil taken from 

 the Elbe district, and at various depths and distances from the 



