1869.] Geology and Paleontology. 121 



In the same number is an article by Mr. H. "Woodward, " On a 

 newly discovered Long-eyed Oalymene, from the Wenlock Limestone, 

 at Dudley." The eye-stalks of the new Trilobite are of remarkable 

 length, and ]\Ir. Woodward has given it the name of Calymene 

 ceratoijlitlialma. 



Those who are specially interested in the subject, will find in the 

 October number of the same magazine, a reprint of Mr. J. Evans's 

 paper " On the Cavities in the Gravel of the Valley of the Little 

 Ouse, in Norfolk," read before the British Association at Norwich, 

 in which the supposed artificial cavities in or near which flint 

 implements were found are referred to sand pipes. 



The concluding portion of Mr. J. A. Phillips's " Notes on the 

 Chemical Geology of the Gold-fields of California " is published in 

 the December number of the ' Philosophical Magazine.' A careful 

 examination of these gold regions has led him to arrive at the 

 following principal conclusions. Quartz veins have been produced 

 by slow deposition from aqueous solutions of silica on the walls 

 of the enclosing fissures. The formation of these veins is often due 

 to hydrothermal agencies, and it may be inferred that they are the 

 result of an intermittent action, the fissures having been sometimes 

 traversed by currents of hot water, and at other times having given 

 off aqueous or gaseous exhalations. It would appear that gold 

 may be deposited from the same solution which gave rise to the 

 formation of the enclosing quartz, and the constant presence in 

 auriferous veins of iron pyrites, which always contain a certain 

 amount of gold, suggests the close connection of this sulphide with 

 the solvent which holds the gold in solution. 



In conclusion, we would call attention to the appearance of 

 Dr. J. J. Bigsby's ' Thesaurus Siluricus — the Fauna and Flora of 

 the Silurian Period,' a notice of which, in greater detail, will be 

 fouQd in another part of this Joui'nal. 



Proceedings of the Geological Society. 



The memoirs published in the last number of the Society's 

 Journal are unusually numerous and interesting. 



In the secondary changes which have modified the chemical 

 constitution of stratified rocks subsequent to their deposition, 

 and produced the various forms of mottling and variegation, 

 perhaps no agent has played so conspicuous a part as Iron, Mr. 

 Maw, in an elaborately illustrated j^aper " On the Disposition of 

 Iron in variegated Strata," has by a series of careful analyses deter- 

 mined many of the appearances connected with ferruginous rocks. 



The state of combination in which iron is usually disseminated 

 is the anhydrous sesquioxide, l)ut it also occurs in small amounts 



