390 Geological Society :— 
Eccles on the Dom du Gouté, about 14,000 feet above the sea-level. 
The rock, which has been fused by the lightning, is a hornblendic 
gneiss. The fusion in the specimens examined is quite superficial. 
The hornblende has been converted into a dark, and the felspar into 
a white, glass, which, as a rule, remain distinct. The fulgurite in 
some cases consists of small spheres of glass, mostly of dark colour, 
which, in one instance, appear to have been spurted over the surface 
of the rock while in a state of fusion. The fulgurite glass is quite 
free from microliths, and shows only gas-bubbles and enclosures of 
glass, the latter usually containing nests of such bubbles. In 
conclusion, a comparison was made between this fulgurite and 
the Bouteillenstein or pseudo-chrysolite of Bohemia, which is now 
regarded by Makowsky and others as an artificially formed glass. 
3. ‘On Brecciated Porfido-rosso-antico.” By Frank Rutley, 
Esq., F.G.8. 
The variety of this well-known hornblende-porphyrite here de- 
scribed shows a distinctly brecciated structure when examined in 
thin section under the microscope. The fragments sometimes 
appear to fit together, at others they are more or less widely sepa- 
rated, so that the section at first sight presents almost the aspect of 
a tuff. Careful examination shows that this brecciated structure 
is due merely to the rock having been crushed and the fragments 
connected in situ by siliceous infiltrations. Delesse’s observations 
upon the varieties of the rock were discussed. A few additional 
remarks were also made upon the mineral constitution of the spe- 
cimens described. 
4, * Fossil Chilostomatous Bryozoa from Aldinga and the River- 
Murray Cliffs, South Australia.” By Arthur Wm. Waters, Esq., 
March 11.—Prof. T. G. Bonney, D.Sc., LL.D., F.R.S., President, 
in the Chair. 
The following communications were read :— 
1. ‘* The Granitic and Schistose Rocks of Donegal and some other 
parts of Ireland.” By C. Callaway, D.Sc., F.G.S. 
The Author first recalled attention to the current theories on the 
nature of the Donegal granitic rock—one which described it as a 
highly metamorphosed portion of a sedimentary series, another which 
regarded it as a mass of Laurentian gneiss. In his view, however, 
it was a true igneous granite, posterior in age to the associated 
schists. In six districts examined it was intrusive and sent out 
veins. The apparent interstratification with bedded rocks was ex- 
plained as a series of comparatively regular intrusions. Where the 
granite was seen in contact with limestone, the latter contained 
garnets and other accessory minerals. No gradation could be dis- 
covered between the granite and any other rock, the junctions (even 
in the case of small fragments of schist immersed in granite) being 
well marked. 
The granite was distinctly foliated. In some localities there was 
merely a linear arrangement of the mica; but near the western 
