96 REPORT— 1871. 



a hot climate. The only mode of getting over this discrepancy is to suppose that 

 in those days the winter cold was very severe, and the summer heat intense, so 

 that in the summer time the animals, now found in warmer regions, migrated north- 

 wards, and in the winter time those now found in the Ai-ctic regions went south- 

 wards. The fourtli group consists of such extinct forms 'as the Cave Bear, the 

 Stag, the Mammoth, and the Woolly Ehinoceros. The tifth gi'oup includes the 

 Sabre-tootJied Tiger, the Irish Elk, Rhinoceros mec/arhinus and R. hemitcecJius, and 

 they, with some others, show that there is no great break between the Quaternary 

 and the Pliocene, such as would warrant any sharply defined division of great 

 value. The interest centered more particularly in the Arctic group ; and so far as 

 the evidence went, it seemed to be extremely probable that they were in occupa- 

 tion of the areas in Great Britain in which they were found during the time 

 the other areas, in which they were not found, v/ere covered with glaciers ; and 

 this period may be put down to that of the latest sojourn of the glaciers in the 

 highest grounds of our islands, and even so far south as the districts of Auvergne 

 and Dauphine. 



On the Progress of the Geohr/ical Surveij in Scotland. By Prof. Geikie, F.E.S. 



When the British Association last met in Scotland, I had the honour of bringing 

 before this Section a report upon the progress of the Geological Survey, from the 

 time of its commencement liere in 1854 by Professor Ramsay, under the direction of 

 the late Sir Henry De la Beche, up to the year 1867, rmder the supen'ision of the 

 present Director, Sir Roderick Murchison. During tlie fom- years which have since 

 elapsed, considerable advance has been made in the suney of the southern half of 

 Scotland ; and I propose now, with the sanction of Sir Roderick, to present to you 

 a brief outline of what has been done, and of the present state of the Survey. 



At the time of my previous report rather more than .3000 square miles had been 

 surveyed. Since then we have completed 2700 square miles additional, making a 

 total area of nearly COOO square miles. Of this area 3175 square miles have been 

 published on the one-inch scale, and three sheets, representing in all G.'32 square 

 miles, are now in course of being engraved. Tlie whole country is surveyed upon 

 the Ordnance Maps on the scale of six inches to a mile, and from these field-maps 

 the work is reduced to the one-inch scale, which is the scale adopted for the gene- 

 ral Geological jSlap of the countrj'. In addition to that general map, however, 

 maps on tlie larger or six-inch are published of all mineral tracts. In this way 

 five sheets of the six-inch maps have now been published, embracing the whole of 

 the coal-fields of Fife, Haddingtonshire, and Edinburghshire, with a large portion 

 of the coal-fields of Lanarkshire, Renfrewshire, Ayrshire, and Dumfriesshire. 



The area over which the field-work of the Survey has extended lies between the 

 mouths of the Firths of Tay, Forth, Clyde, and Solway, eastwards to the borders 

 of Roxburghshire and the mouth of the Tweed. It includes the counties of Fife, 

 Kinross, the Lothians, Lanark, Renfrew, Peebles, Ayr, Wigton, Kirkcudbright, 

 Dumfries, and Selkirk, with parts of Stirling, Dumljarton, and Perth. 



Of the geological formations examined, the Lower Silurian rocks of the southern 

 uplands cover a considerable space upon the published maps. LTntil three years 

 ago the mapping of tliese rocks continued to be most unsatisfactory, owing to the 

 want of any continuous recognizable section from which the order of succession 

 among the strata could be ascertained, and to tlie great scarcity of organic remains. 

 Our more recent work among the Leadhills, however, has at last given us the means 

 of imravelling, as we hope, the physical structure and stratigraphical relations of 

 the uplands of the south of Scotland. The rocks there are capable of division into 

 several well-marked groups of strata, characterized by distinct assemblages of fos- 

 sils. We have a lower or Llandeilo series, with a suite of graptolites, and forming 

 probably an upper part of the Moftat group, and a higher or Caradoc set of beds, 

 with a considerable assemblage of distinctive fossils. This higher gi-oup we be- 

 lieve to be on the same general horizon as the limestones of Wrae and Kilbucho in 

 Peeblesshire. 



The Lower Old Red Sandstone has now been mapped completely over the whole 

 of its extent between Edinburgh and the south of Ayrshire, f'ossils have only 



