90 Correspondence — Prof. T. G. Bonney. 



CRYSTALLINE SCHISTS OF THE LEPONTINE ALPS. 



Sir, — Permit me to express my sincere regret to Dr. StapfF for 

 having abbreviated not only his name but also — what is worse — his 

 life. How the second misconception arose I cannot tell, but it is 

 certainly not a recent one. Perhaps I ought also to apologize for 

 not referring to his papers more frequently, but the truth is that I 

 have only seen one of them, and that (for reasons on which it is need- 

 less to enter) I had but little opportunity of consulting. For this 

 neglect some of my fellow-workers will probably visit me with 

 censure. Be it so, I can only say that I do not always find myself 

 quoted "over the water," and in this matter take as my maxim : 

 lianc veniam petimusqiie danmsqiie vicissim. 



Except for this, my only purpose in writing, is to excuse myself 

 from discussing at present Dr. Stapff's friendly and interesting com- 

 munication. I am still at work on the subject of that singular 

 complex of rocks in and about the Urserenthal, and cannot publish 

 aiij'thing more till I have tested certain hypotheses on the ground. 

 This I fear cannot be done during the present summer, since I an- 

 ticipate that my steps must be turned in another direction, and I am 

 not one of those fortunate persons who can undertake a long journey 

 at pleasure in order to investigate a geological problem. 



So I ask permission only to observe : — 



(1). That I do not deny the possibility of Jurassic rocks or 

 Carboniferous rocks entering into the complex of the Urserenthal. 

 But I doubt the occurrence of organisms in the Altkirche marble. 

 Without seeing the slides, it would be difficult to express an opinion 

 on the nature of the objects figured by Dr. Stapff on page 18 of 

 this volume; the upper one certainly has an organic aspect; the 

 lower strikes me as more doubtful. But the nature of the objects 

 is not the only thing to be considered. 



(2.) That, if I am right in understanding Dr. Stapfi^ to assign the 

 Piora schists to the Carboniferous system, this identification appears 

 to me only an hypothesis. If there be any valid evidence in favour 

 of it, this is unknown to me, while I am aware of some serious 

 difficulties in which we should be landed by accepting it. 



(3.) That, from what I know of crystalline rocks and their ways, 

 I venture to doubt the accuracy of the identification (p. 17) of "rolled 

 quartz grains (sand) in some beds of the Guspis micaceous gneiss." 

 For years I hunted for traces of an original clastic structure in 

 gneisses and certain associated crystalline schists, longing to find them, 

 but in vain. Again and again I have seen them curiously simulated 

 here and there, by the results of pressure, and so, having been often 

 taken in for a while, I have become rather sceptical. 



T. G. BoNNEY. 



CONCHOLOGICAL NOMENCLATURE. 

 Sir, — Mr. A. J. Jukes-Browne, in the January Number of the 

 Geological Magazink, takes objection to some points in Concho- 

 logical Nomenclature adopted in the " Systematic List of the F. E. 



