Reports & Proceedings — Edinburgh Geological Society. 527 



one of the several species that are represented in the material, 

 enough has been done to show that, given a sufficient number of 

 sections, the structure of the body and limbs could almost certainly be 

 worked out, even if no entire specimens should be brought to light." 

 During 1918 Mr. D. Tait, H.M. Geological Survey, obtained 

 additional specimens of chert from the Rhynie outcrop, to be examined 

 by Dr. Caiman and Mr. Scourfield. A grant from the Royal Society 

 has been received to aid the investigation. 



III. — Edinbtjbgh Geological Society. 

 March 19, 1919.— Mr. John Mathieson, F.R.S.G.S., Vice-President, 



in the Chair. 



1. "Acid Potassium Sulphate as a Petrochemical Test and 

 Solvent." By Dr. Wni. Mackie, M.A., Elgin. 



An abstract of this paper was given by Dr. Campbell. It is 

 a record of a comprehensive research on the action of acid potassium 

 sulphate as a petrochemical test and solvent, as applied to the study 

 of residues of heavy minerals in Scottish granite, and sedimentary 

 rocks. These residues when acted upon by this solvent, in a state of 

 fusion, displayed certain changes in colour, characteristic etching 

 marks, and other phenomena by which they could be readily 

 distinguished under the microscope. Dr. Mackie describes certain 

 methods of treating these mineral residues, and subsequently 

 mounting them on microscopic slides for study and recognition. 



2. " Chemical Analysis of the Dolerite and Hornfels of 

 Auchinoon." By Mr. T. Cuthbert Day, E.C.S. 



This paper gives a record of eight complete chemical analyses of 

 the rocks of Auchinoon, including the intrusive dolerite and the 

 overlying hornfels with which it is in contact. The differences in 

 the appearance and composition of the dolerite as found about 10 feet 

 below the junction, and at the junction itself, were pointed out, 

 and also the variations in the analyse^ of the hornfels at the junction 

 itself and at increasing distances from it. An analysis of the clay 

 band overlying the hornfels was also given. 



IV. — Liverpool Geological Society. 



The annual meeting of this Society, inaugurating the Sixty-first 

 Session, was held at the Roval Institution, Liverpool, on October 14,. 

 1919. Mr. W. T. Walker, B.Sc, F.G.S., was elected President, and 

 Professor P. G. H. Boswell, O.B.E., D.Sc, E.G.S., Vice-President. 



The retiring President, Dr. J. C. M. Given, F.G.S., delivered an 

 address on ''The Divisions of the Pleistocene", which was devoted to 

 a review and criticism of the results of recent work on this latest 

 period of geological history. Eor the purpose of subdividing the 

 epoch, palaeontological methods might be employed, and the 

 mammalian fauna enabled three distinct life zones to be defined, 

 viz.: (1) that of a warm climate represented by JElephas antiquus ; 



(2) that of a cold climate with E. primigenius, etc. ; and finally 



(3) that of a more genial climate with Rangifer tarandus and Cervus 

 giganleus. These faunal divisions are useful, but they overlap very 

 much, and are not numerous or sharp enough to be of great scientific 



