depth ; 30 feet in some cases mentioned by Mr. Smith. The 

 Paisley fields are to the north-west of the railway station ; they yield 

 a good many species. At Dalmuir, north of Erskine, a shelly deposit 

 described by Dr. Thomas Thomson* has yielded 70 species. Beds 

 on the east shore of Lochlomond, two miles north-west of the mouth 

 of the Endrick, and 10 feet above the highest level of the lake ; also 

 beds at the south-east angle of the lake, and on the summit of Inch 

 Lonach island opposite Luss, gave to Mr. Adamson about 12 

 species. f Captain Laskey found 22 species four miles from Glasgow, 

 in cuttings of the Paisley Canal, 40 feet above the level of the 

 Clyde. J The age of these beds has not been accurately determined ; 

 it must depend upon the proportion of Arctic species ; but they seem 

 referable to the upper or post-pleiocene division. Space does not permit 

 an enumeration of other cases, of which several might be mentioned 

 at much greater altitudes, though not in the vicinity of Glasgow. 

 The shells are generally of a littoral character, much worn and broken, 

 and about 160 species have been noticed. Of the same age and con- 

 nected with these are many sand, gravel, and clay beds without shells. 



The Boulder Clay. 



6. This remarkable deposit, whose original mode of formation has 

 excited such active discussion among geologists, was long since 

 noticed by Col. Imrie, Mr. Bald, and other writers, as the old alluvial 

 cover spread out over the surface of the coal fields and trap rocks of 

 Scotland. But it is to Mr. Smith we owe its establishment as a 

 definite group, with peculiar organic contents. || It may, perhaps, be 

 best divided into three subordinate groups : 1st, upper Till, with finer 

 and smaller boulders than those of group No. 3, of lighter colours, and 

 unstratified ; 2d, stratified beds, in which chiefly the shells and other 

 remains occur ; and, 3d, the lower Till, resting frequently on the car- 

 boniferous rocks, and consisting of stiff blue or red clay, confusedly 

 mixed with boulders, and unstratified. In the Till proper, shells are 

 rare, and when found, fragmentary ; but the stratified beds have yielded 

 a great number of species, and of these from 10 to 15 per cent, are 

 either extinct or not now known in the British seas. Those which 

 are recent, but not found in the British seas, occur in the Arctic 

 regions, and indicate therefore the existence of a colder climate than 

 that of the present period, and colder also than that under which 



* Rec. Gen. Science, i., 131. f Wern. Mem., iv., part ii., 334. 



\ Wern. Mem., iv., part ii., p. 568. 

 Ibid, several vols. 



|| Ibid, viii. Proceed. Geol Soc., ii., 427 ; and iii., 118, 149. Trans. Geol Soc., 

 vi., 2d series, p. 153. Jour. Geol Soc., ii., 33 ; v., 17, 



