Geological Society of London. 235 



river-channels are also described — one at Koru Ombo, and the other 

 at Assuan itself. The author discusses the mode of origin of the 

 second terrace and the old river- valleys, and believes them to be due 

 to the former greater volume of the river, and not to subsequent 

 erosion of the valley. He gives further evidence of the existence 

 of meteorological conditions sufficient to give rise to a " pluvial " 

 period, and points out that other authors have also considered that 

 the volume of the Nile has been greater in former times. 



4. " The Fauna of the Keisley Limestone. — Part I." By F. R. 

 Cowper Reed, Esq., M.A., F.G.S. 



The author has examined a very full series of fossils from the 

 Keisley Limestone of Westmoreland, and proposes to describe the 

 fauna of the limestone. In this (first) part of the paper a description 

 of the trilobites is given. He recognizes about forty species, belonging 

 to ten families. Several of the forms are new, whilst others have 

 previously been described, and many of them occur in the limestone 

 of the Chair of Kildare and the Leptana-limestone of Dalecarlia. 



II.— March 11th, 1896.— Dr. Henry Hicks, F.R.S., President, in 



the Chair. 



The President announced that, in connection with the Hungarian 

 Millennial Exhibition, a Congress of Mining and Geology would be 

 held at Budapest on September 25th and 26th, 1896. 



The following communications were read : — 



1. " On an Alpine Nickel-bearing Serpentine with Fulgurites." 

 By Miss E. Aston, B.Sc. With Petrographical Notes by Prof. T. G. 

 Bonney, D.Sc, LL.D., F.E.S., V.P.G.S. 



The specimens described were collected on the summit of the 

 Eiffelhorn (near Zermatt) by Prof. W. Ramsay, F.R.S., and J. Eccles, 

 Esq., F.G.S. As they showed some very well-marked " lightning- 

 tubes," the former thought that possibly analyses might prove 

 interesting. These were undertaken by Miss Aston at University 

 College, London. The rock is a serpentine, somewhat schistose from 

 pressure, which has been formed by the alteration of a rock chiefly 

 composed of olivine and augite. One of the analyses gives 4-92 

 per cent, of nickel oxide and hardly any lime. Prof. Bonney 

 detected some awaruite under the microscope, but not nearly enough 

 to account for the analysis. Reasons are given to show that the 

 nickel oxide probably replaced lime in the pyroxenio constituent of 

 the rock. 



The tubes, about tV inch in diameter, are round in section, cleanly 

 drilled, and lined with a verv thin film of dark-brown or black 

 glass. The microscopic structure of this is described, as well as 

 that of glass made by melting the rock with a blow-pipe (using 

 oxygen). Some fulgurite-glass from the Hornli has also been 

 examined (much resembling that described by Mr. Rutley from 

 Monte Viso), and an analysis of this rock is given. 



2. " The Pliocene Glaciation, Pre-Glacial Valleys, and Lake- 

 Basins of Subalpiue Switzerland ; with a Note on the Microscopic 



