214 Messrs. Parker and Jones on 



k. preuss. Akad. Wissenscli. Berlin' for 1843) was noticed at 

 large in the ' Quart. Journ. Geol. Soc.' vol. i. pp. 251 &c., as 

 illustrative of the influence of microscopic life on recent and 

 fossil stratified accumulations. 



In these memoirs, and in shorter collateral notices in the 

 ' Monatsbericlite ' of the Berlin Academy of Sciences*, Dr. 

 Ehrenberg treated of numerous Diatomacege (Poljgastrica), 

 Polycystina, Foraminifera (Polythalamia), Spongoliths, and 

 other microscopic organisms, which he had found, either 

 recent, especially in the Red Sea, the Mediterranean, and the 

 North Sea, or fossil in numerous deposits of various ages, 

 such as the Mountain-limestone, Oolite, Chalk, Tertiary, and 

 Posttertiary strata. Some few of the recent and fossil species 

 were figured by him in the ' Abhandlungen ' for 1838 and for 

 1839 (see pp. 218 & 221) ; but it was not until 1854 that Ehren- 

 berg was enabled to fulfil his earnest and laudable desire to 

 give to the world faithful and manifold portraits of the well- 

 prepared and almost innumerable microscopic objects on which 

 his published opinions had been founded. The second part f 

 (middle third) of the magnificent folio volume entitled '■ Mikro- 

 geologie,' published under the patronage of Frederick- William 

 the Fourth of Prussia, consists of 41 plates J, illustrating the 

 Microliths, Microphytes, and Microzoa to which his memoirs 

 refer. Explanations of the plates, with a full index, are given, 

 but no descriptive text ; most of the specimens, however, are 

 alluded to in other portions of the book, and in the ' Monats- 

 bericlite.' 



On the Diatoms, Polycystines, Spongoliths, G eoliths, and 

 Phytoliths here illustrated we do not offer any remarks ; but 

 we have busied ourselves with the beautiful engravings of the 

 Foraminifera in the ' Mikrogeologie,' that we might bring 



* Namely, Monatsb. fiir 1838, p. 104, flint from Volhynia ; pp. 192- 

 200, Microzoa mainly constituting Chalk ; fur 1840, pp. 18-23, Forami- 

 nifei'a of the North Sea ; fiir 1844, pp. 74-96, new genera and species of 

 Foraminifera ; pp. 206, 207, Microzoa from the South-polar Sea; pp. 245- 

 248, Spirohotrys cegea ; pp. 274, Microzoa from Kurdistan &c. ; p. 414, 

 Microzoa of the Chalk ; fiir 1858, pp. 10-30, new genera and species from 

 the^Egean and Mediterranean; pp. 118-128 and 295-311, siliceous casts 

 of Foraminifei'a. 



t The other parts of this grand work consist, — the first of catalogues, 

 special and collective, of the microscopic objects, animate and inanimate, 

 from 836 different freshwater deposits from all parts of the world, ex- 

 cepting North America ; the third part contains notices of North- American 

 microscopic life and microgeology, with special and collective catalogues 

 of the objects found in upwards of 300 filterings, river-muds, and other 

 deposits from the United States. 



\ Comprising four thousand figures, in great part coloured, and all 

 (except in pi. 40) magnified at least 300 times linear. 



