Geological Society of London. 429 



from being proved by him to be truly of sedimentary origin, are of a most questionable 

 origin, since they are neither in themselves fossiliferous, nor can they be correlated 

 with any containing fossils as proofs of true sedimentary deposition ; and the descrip- 

 tion of his section is sufficient to show this ; for although it looks well on paper on a 

 scale of three feet to the mile, the author has so little confidence in it that he is not 

 even certain as to which is the top or bottom of the section on which so much generali- 

 zation is based. (4) That a parallel structure equally, if not better, developed than 

 any occurring in the gneiss of Donegal is common to many volcanic rocks, as in a 

 specimen laid before the meeting, in which this parallel foliated structure, due to 

 crystallization-layers, is so well developed as to make it appear exactly like a strati- 

 fied rock, and even split along these lines, and this, although the product of volcanos 

 still active is found for great distances both overlying conformably and intercalated 

 between beds of the Cretaceous and Oolite formations. 



Mr. Scott was unwilling to accept the section given by the author as satisfactory. 

 He agreed, however, as to the bedded appearance of the granite, and to the masses 

 lying in general conformably with the lines of stratification of the country. The 

 nearest spot at which fossiliferous rocks occurred was separated fi-om the beds de- 

 scribed by the whole width of the county of Tyrone, though some presumed Eozoonal 

 forms had been found at a less distance. He was not prepared to believe in the 

 original absolutely fused condition of granite, nor in there being two distinct forms 

 under which it occurred. 



3. "Memoranda on the most recent Greological Changes of the 

 Elvers and Plains of Northern India, founded on accurate surveys 

 and the Artesian well-boring at Umballa, to show the practical 

 application of Mr. Login's theory of the abrading and transporting 

 power of water to effect such changes." By T, Login, Esq., F.E.S.E. 

 Communicated by Alfred Tylor, Esq., E.G.S. 



The author commenced by referring to the general conditions of 

 the surface of the country under consideration, and to the evidence 

 afforded by it of a great decrease in the amount of rainfall, and a 

 great change in the nature of the rivers. His object was to show 

 that the superficial deposits of the plains of Ladia were formed by 

 the action of mountain streams, the deposits being irregular trans- 

 versely, but exhibiting a uniform section longitudinally, in a curve 

 which the author believed to be a true parabola, as indicated by Mr. 

 Tylor. The connexion of this with the author's theory as to the 

 transporting power of water was indicated. The author also showed 

 that the beds of the large Indian rivers are rising rather than being 

 lowered, and pointed out that this was in accordance with his theory. 



coiaiRESi^on^riDiEi^ciE. 



DENUDATION OF THE SHROPSHIRE COAL-FIELD, i 

 Sir, — I regret to find that I have read the passages contained in 

 Mr. Eandall's letter to the Mining Journal in a sense which the author 

 had not intended; and I hope he will acquit me of any desire 

 wilfully to misrepresent his views. I am well satisfied to find there 

 is really no difference of opinion between us on the general question 

 whether the denudation took place before or after the main faults of 

 the Coal-measures. He refers, however, to a local instance of faults 

 having protected the Coals at Halesfield. I think it would help 

 forward the scientific inquiry if he would kindly furnish us with 

 the data which have led to this impression — or rather opinion — that 

 1 Geol. Mag., 1871, Yol. VIII., p. 200. 



