220 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Jan. 25, 



Mr. Russell (the original discoverer of the shells) reports that the 

 shell- clay occupied a kind of basin in the Lower Till, the section 

 being the following : — 



ft. in. 



I. Clay (supposed to be true Boulder-clay) 14 



II. Clay, finer, containing smaller stones, with Telh'na 



calcarea, Cyprina Islandica, and a large Balanus 



in the deepest part, but rapidly thinning out .... 2 1 



III. Boulder-clay, resting on Carboniferous beds .... 



With great kindness, Mr. Russell sank a fresh well, seven yards 

 from the old one, and the following section was exposed : — 



I. Surface soil 1 



II. Upper clay 5 3 



III. Boulder-clay, not pierced through 9 6 



The following observations were made : — 



1. There were decided distinctions between the upper and the 

 lower clays. The stones were most finely polished in the lower 

 bed ; but in the upper, only a few stones had slight indications 

 of striation, and these were nearly obliterated. The upper clay 

 itself was looser and more easily worked than the lower. The line 

 of division Avas so marked as easily to be traced by the workmen 

 engaged in the operation, who found a great difference in the labour 

 required. 



2. The Lower Boulder-clay of the well is exactly similar to that 

 observed in an old brick-field about a mile and a^half distant, form- 

 ing the base on which a fine brick-clay rests, from which shells have 

 been taken by Mr. Russell. 



3. The junction between the two clays was recognized by Mr. 

 Russell as the exact position at which he had found the original- 

 shell-bed. 



4. The beds in the well dipped to the N.E., towards the shell-bed, 

 in such a way as to form exactly the basin within which it rested. 



Taking these observations into consideration, and remembering 

 that the new well is within seven yards of the old, with a rapid dip 

 of the strata towards it, it will appear at least doubtful whether 

 the shell-bed was intercalated between two Boulder-clays (in the 

 true sense), and very probable that it rested upon the old Boulder- 

 clay, in the normal position of the corresponding beds through the 

 Clyde district, and was covered by that Upper Drift which is per- 

 fectly familiar to local students. 



As regards this upper clay, indeed, the whole aspect of the 

 country shows how easily it might have been the wash from a ridge 

 of true Boulder-clay, which rises above it, and against the slope of 

 which it rests. 



There are within sight numerous isolated hills of Boulder-clay, 

 rising like towers to heights of twenty and thirty feet, and long 

 ridges of the same material sweep round and form large basins. 

 In the immediate neighbourhood also is a large fault, forty-four 

 fathoms to the N.E., another, of seventy-five fathoms, to the S.W., 



