453 
Resume Meteorologique de l’annee 1859 pour Geneve et le Grand 
Saint Bernard. Par E. Plantamour. 8vo . — From the Author . 
Observation de l’Eclipse Totale de Soleil du 18 Juillet 1860. Par 
E. Plantamour . — From the Author. 
Observations Astronomiques faites a PObservatoire de Geneve 
(1855-56). Par E. Plantamour. 4to . — From the Author. 
Mesures Hypsometriques dans les Alpes. Par E. Plantamour. 
4to . — From the Author. 
Journal of Proceedings of Linnean Society, Vol. V. No. 19 . — From 
the Society. 
Almanaque Nautico para 1862. Cadiz, 1860. 8vo.-^-From the 
Observatory of St Fernando. 
Monday , 15^ April 1861. 
The Hon. LORD NEAVES, Vice-President, in the Chair. 
The following Communications were read : — 
1. Additional Observations on the Chronology of the Trap- 
Rocks of Scotland. By Archibald Geikie, Esq., P.G.S. 
In a communication made to the Society last session, the author 
stated the results of a series of explorations among the trap-rocks 
of Scotland, and showed that, at successive periods, during the depo- 
sition of the Lower Silurian, Old Red Sandstone, Carboniferous, 
Oolitic, and Tertiary formations, there were contemporaneous erup- 
tions of volcanic material. During the year 1860, the investigation 
was continued across the Highlands into the Inner Hebrides, and 
throughout a large part of the central counties southward to the 
Cheviot Hills. The author was now able to fill in more fully what 
had only been sketched in outline in the previous paper, and to pre- 
pare a series of maps to illustrate the volcanic areas of Scotland 
during the successive geological periods. He showed that, in the 
Scottish Highlands, no distinct trace existed of any igneous rock 
erupted contemporaneously with the deposition of those Lower 
Silurian strata which are now metamorphosed into gneiss, mica- 
schist, clay-slate, &c. The greater part of his observations during 
the past year had been devoted to the elucidation of the chronology 
of the igneous rocks belonging to the period of the Old Red Sand- 
