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XLI1. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



June 19, 1878.— John Evans, Esq., D.C.L., F.B.S., Vice-rresident, 



in the Chair. 



[Continued from p. 235.] 

 nnHE following communications were read : — 

 -*- 2. " Notes on the Palaeontology and some of the Physical Con- 

 ditions of the Meux's-Well Deposits." By Charles Moore, Esq., 

 E.G.S. 



The author remarks that the various deep-well borings around 

 London have abundantly proved the correctness of Mr. Godwin- 

 Austen's inference that the Palaeozoic axis of the Mendips is con- 

 tinued beneath the Secondary rocks of the south-eastern counties. 

 Mr. Moore has himself shown that where these Palaeozoic rocks 

 finally disappear under the Secondary strata, there are found at the 

 unconformable junction of the two formations a set of deposits in- 

 dicating the existence of very peculiar physical conditions, and con- 

 taining an admixture of fossils from very different geological hori- 

 zons. Hence he was led to inquire whether any trace of similar 

 abnormal deposits might be found in the deep-well borings of 

 London. 



With this view he set to work at washing some of the materials 

 supplied to him from the Meux's well, and studying the minute and 

 often microscopic organisms thus obtained. 



The Chalk was not particularly examined ; but from a single small 

 sample of Upper Greensand he obtained numerous Eoraminifera and 

 Entomostraca, including one Cyprid new to science. 



The Gault yielded 1 6 genera and over 30 species of Eoraminif era, 

 and 20 species of Entomostraca, 4 of which are new, together with 

 many young forms of Gasteropods and Cephalopods. 



But the chief interest of Mr. Moore's investigations centres in the 

 67 feet of strata intervening between the Gault and Devonian. In 

 this marly and oolitic-looking deposit he found no less than 85 dif- 

 ferent kinds of organisms, exhibiting a singular admixture of marine 

 and lacustrine forms of life. Eoraminif era are rare, but Entomostraca 

 and Polyzoa are very abundant. Some genera are found, such as Car- 

 penieria, Saccammina, Thecidium, and Zellania, of which the range in 

 time is greatly extended by these investigations. 



The author fully confirms Mr. Etheridge's reference of the beds 

 in question to the Neocomian period, widely as they differ in phy- 

 sical characters from the Lower Greensand strata of the south-east 

 of England. From a careful study of the nature and condition of 

 preservation of the minute organisms he concludes that the deposits 

 which contain them were formed at first in shallow lacustrine hollows 

 on the surface of the Devonian rocks now lying buried at a depth of 

 1000 feet below London, and that these lakes were invaded by the 

 waters of the Neocomian sea, with the deposits of which their sedi- 

 ments were in part mingled, and under which they were finally buried. 



