Correspondence — Mr. F. Ridley — Prof. J. F. Blake. 285 



after whicli they became finally extinct. The author, in conclusion, 

 referred to the various localities from which he had obtained " cone- 

 in-cone," and stated that in the Scottish coalfield the structure seems 

 to be always associated with strata in which the contained organisms 

 indicate a freshwater and lacustrine origin for the beds, and that the 

 deposits were therefore probably formed within the areas of wide and 

 shallow lakes. 



coi^ E-iBsi^ojiNriDEisroiE. 



THE ENSTATITIC LAVAS OF EYCOTT HILL. 



Sir, — With reference to the interesting paper by Prof. Bonney 

 on the Enstatitic Lavas of Eycott Hill, which appeared in the last 

 Number of this Magazine, I venture to make the following remarks. 



At the time when Mr. Ward wrote his memoir on the Geology of 

 the northern part of the Lake District, the term andesite was not in 

 use, except as a synonym for andesine felspar. At that period the 

 rocks now termed andesite were called basalt or dolerite. 



The determination of rhombic pyroxene in rocks of this class had 

 not then been made, at all events in this country, and the researches 

 of Whitman Cross, Iddings and Teall have been published long since 

 Mr. Ward's death. Although, therefore, enstatite exists in the 

 Eycott Hill Lavas, as now shown by Prof. Bonney, it is not sur- 

 prising that Mr, Ward did not suspect its presence. This is the 

 less to be wondered at when we consider that he laboured under the 

 great disadvantage of working with a microscope which had no 

 rotating stage or appliances for determining the precise directions of 

 extinction in crystals. 



It is, I think, only justice to a departed friend and colleague to 

 offer these explanations. Frank Eutley. 



93, Edith Koad, "West Kensington. 



THEORY OF FAULTS. 



Sir, — I have referred to Captain Button's note on Malta, and 

 quite agree with him that the explanation he gives of downward 

 ending faults may be the right one. What I inquired was, if any 

 geologists knew of upward-endimg faults in one set of strata ? 



While I am writing on this subject, will you allow me to add that 

 as some of my friends have expressed disapproval of the tone of my 

 criticisms on Mr. Fisher's paper, I regret that I was led to adopt 

 it. I had no intention of being either personal or ofi'ensive. 



Doubtless we all have our weaknesses, and if each were to be 

 attacked in a similar manner, harmony would soon be at an end. 



Nottingham, April 29, 1885. J. E. Blake. 



EOMALONOTUS CRASSICAUDA, SANDB., FROM SOUTH DEVON. 



Sir, — The remains of Homalonoti from British Devonian beds, 

 which were known at the time, having been described by yourself in 

 the Geol. Mag. for November, 1881, and April, 1882, it appears to 



