188 Royal Geological Society of Ireland. 
namely, the evidences of enormous earth-movements and horizontal 
displacement in the Highlands. And secondly the arguments in 
support of a Paleozoic, or Carboniferous to Permian, Glacial period. 
With regard to the former, the revelations announced by the officers 
of the Geological Survey as to transplacement, metamorphism, and 
deformation of the rocks, were brought to notice, and amongst 
theoretical or other observations bearing upon the question of how 
the rock-masses were afforded room to move, the late observations 
by Dr. Ricketts in the Guotoercan Macazrne were referred to ; also 
Mr. J. R. Kilroe’s suggestions, which would go far to afford a 
solution of the question. These suggestions, now for the first time 
advanced, indicated that where areas of locally reduced vertical 
pressure came into existence, by bulging of the crust, in consequence 
of contraction in cooling or other cause, the greater vertical pressure 
on each side of such an area (possibly increased by the deposition of 
denuded materials from the elevated part) would produce attenuation 
of the underlying rocks. The pressed-out substance of these flowing 
—after the manner described by Tresca and Daubrée—towards the 
space beneath the area of least pressure, crumpling and folding of 
beds, in this position, would result. This need not necessarily be 
accompanied in such situations by metamorphism. but beneath regions 
of extreme superincumbent pressure, once the cosmical equilibrium 
was disturbed and motion originated, metamorphism would proceed 
actively till equilibrium was restored. Repeated action of this kind 
would produce alternating zones of greater or less, or no, meta- 
morphism, and where the vertical pressure and consequent movement 
on each side of an elevated area of least pressure differed in amount, 
the tangential thrust of the rock-masses, moving in opposite 
directions towards each other, would vary, the most powerful 
thrust tending to pass over the other with a more and less upward 
inclination towards the place of least pressure and least resistance at 
the surface of the elevated area. Development of these actions 
where the scene of the elevation had changed to a previously altered 
region, would account for most of the phenomena which form the 
key to the latest published interpretations of Highland geology. 
Regarding the second subject, the address pointed out that since 
the time when the Rev. Dr. Haughton recorded, thirty-eight years 
ago, the occurrence of glacial boulders of granite in the Carboniferous 
limestone of Dublin, a great number of writers, including Dr. Blan- 
ford, President of the Geological Society of London, had advocated 
the existence of glacial features in connexion with Permian or 
Carboniferous boulder-beds. Amongst these writers was Sir A. C. 
Ramsay, who recognized first the glacial character of certam Permian 
deposits in England, but numerous other writers had maintained the 
same character for beds in India, Afghanistan, South Africa and Hast 
Australia, regions supposed to have been once united by Sclater and 
Haeckel’s lost continent of ‘Lemuria.’ Attention was called to the 
latest contribution to the geological literature of the subject by 
Dr. Waagen of Prague, who contends that the ancient Carboniferous 
Ice Age prevailed over the whole earth except South America, and 
