TRANSLATIONS AND NOTICES 



GEOLOGICAL MEMOIRS. 



1. On the Remains of Infusorial Animalcules in Volcanic 

 Rocks. By C. G. Ehrenberg. 



[The present article has been prepared from two communications made by Prof. 

 Ehrenberg to the Royal Academy of Sciences at Berlin, and published in the 

 ' BericJite' (Proceedings) of that Academy for September 1844 and April 1845. 

 It has not been thought necessary to reprint the lists of species and the diagnostic 

 description of the new species, since these may be referred to in the pages of the 

 ' Berichte.'— Ed.] 



The influence of animalcules (or organic bodies so minute as to be 

 invisible to the naked eye) on the formation of the actual solid masses 

 which make up the earth's crust has only lately been recognised, even 

 with regard to the newest stratified rocks and those of the most 

 recent geological period ; but amongst these the so-called mountain 

 meal, peat, sea and river-mud, bog-iron, the earth in which the 

 mineral Vivianite occurs, and others, are now known to be either 

 partly or entirely composed of the oj'ganic products secreted by 

 these little animals. 



A similar origin must however now be assigned to those tertiary 

 rocks which are known by the names tripoli, polishing slate and 

 semi-opal, to some of the porcelain earths, to the so-called dysodil, 

 and to the paper-coal of the brown coal formation ; and even among 

 the upper secondary rocks we find that the greater part of the white 

 chalk, the nummulite and catacomb limestone of Egypt, the firestone 

 of the same period, and several of the chalk marls, are, beyond ques- 

 tion, the direct products of similar minute organic beings. 



Amongst the middle secondary rocks, again, we find that the 

 hornstone of the coral rag of Cracow and some widely-spread oolitic 

 rocks in various parts of Europe exhibit distinct traces of a similar 

 origin ; while oven in the newer })alaeozoic rocks we learn from Count 

 Keyserling and Prof. Blasius that there is a compact limestone of 

 the carboniferous period near Lake Onega in whicii these little or- 

 ganic bodies are present in vast abundance, associated with a species 

 of Bellerophon. 



The hornstone of Tula also, considered and described by Hel- 



VOL. II. PART II. H 



