On Drift-beds in the West of Scotland, 399 



to mislead an observer in examining such accumulations. He then 

 described the various sections of the deposits, and showed that the 

 lowest bed is a hard tough unstratified clay, full of striated, 

 smoothed, and polished stones of all sizes, but totally devoid of 

 fossils, and that it is, in fact, the true old Boulder-clay of the geo- 

 logists of the West of Scotland. The Shells are entirely confined, to 

 a bed of clay of open texture, containing a few small stones ; it rests 

 immediately on the Boulder-clay as above defined, and is succeeded 

 by various drift-beds, consisting of seams of clay and sand inter- 

 mingled, containing stones that are rarely striated, and without 

 Shells. 



Dr. Bryce then discussed the probable origin of these drifts, and the 

 amount of depression which the land had sustained before the Shell- 

 bed was deposited over the Boulder-clay, which he considered to 

 have been formed by land-ice emanating from central snow-fields, 

 and covering the whole surface of the country. 



3. " On the Occurrence of Beds in the West of Scotland in the 

 position of the English Crag." By James Bryce, M.A., LL.D., F.G.S. 



In consequence of the results arrived at from the investigation of 

 the Drift-beds of Arran, Dr. Bryce determined to examine all the 

 recorded cases of fossils occurring in the Boulder-clay, the Chapel 

 Hall case having, however, been already undertaken by the Rev. H. 

 W. Crosskey. The most celebrated case is that of the occurrence 

 of Elephant-remains at Kilmaurs, near Kilmarnock, in Ayrshire ; 

 and the author showed, from a section of the quarry exposed for the 

 purpose by Mr. Turner, of Dean Castle, which corresponded exactly 

 with one already furnished to him by an aged quarryman, that the 

 Elephant-remains, the Reindeer's horn, and the Shells, all occurred 

 in beds below the Boulder-clay, and not in that deposit, as has 

 always been stated. The same conclusion was arrived at respecting 

 the occurrence of Elephant-remains at Airdrie and Bishop briggs, 

 and of Reindeer's horn with Shells at Croftamie ; and the author 

 concluded by discussing the question whether the fossils belong to 

 the Upper Crag period, or merely indicate a downward extension of 

 the Arctic fauna which characterizes the beds directly above the 

 Boulder-clay, as described in the last paper. 



4. " On the Tellina proximo, Bed at Chapel Hall, near Airdrie." 

 By the Rev. H. W. Crosskey. 



One of the most perplexing cases in Scotland, upon any theory of 

 the formation of Boulder-clay, has been the alleged occurrence at 

 'Chapel Hall of a clay-bed containing Tellina proximo,, intercalated 

 between two masses of true Boulder-clay. The Shells were first 

 found by Mr. James Russell in sinking a well ; and the case was 

 made known by Mr. Smith, of Jordan Hill, in a paper laid before the 

 Geological Society in lb50. At the author's request, Mr. Russell 

 had sunk another well 7 yards from the former, from an examina- 

 tion of which Mr. Crosskey satisfied himself that the bed above 

 that containing the Shells is not the true Boulder- clay, but an 

 upper Drift, and that the Shells occurred in a hollow of the lower 

 clay, or true Till, filled up with a clay-deposit of an age interme- 



