1814.] Bed of fossil Shells on the Bank? of the Forth. 135 



or muscles of any extent so far up the river, nor nearer than eight 

 or ten miles. By what cause then, and at what time, have these 

 shells been deposited in their present situation ? 



When I first examined this bed of fossil shells, in 1S06, I was 

 disposed to draw from it a proof of the gradual diminution of the 

 waters of the ocean, and the retreat of the sea from the British 

 shores. Several years afterward I read a short paper to the Wer- 

 nerian Society on the subject, which has been quoted by Professor 

 Jameson in his notes to Von Buch's Travels through Norway, page 

 21 S, as connecting the geological phenomena of Scotland with 

 those of Norway. In the latter country Von Buch observed at 

 various places beds of sea shells at different degrees of elevation 

 above the sea. At Tromsoe he found them at 20 feet, at Luroe 

 nearly -iO feet, at Hundolm 30 feet, and at Iteenkiar between 400 

 and 5()'> feet above the surface of the bay. In the last mentioned 

 situation the shells occur in a blue marly clay, and must have been 

 deposited ai the same period with the clay. In the other places 

 where these shells have been observed, they are found much broken 

 and comminuted. In several places of Scotland appearances 

 similar to those observed in Norway have been traced. 



At Paisley sea shells are found imbedded in a stratum of sand and 

 clay nearly forty feet above the present level of the Clyde. This 

 bed has been described by Captain Laskey. (Annals oj Philosophy^ 

 vol. iii. p. 150.) The ground on which the Botanic Garden of 

 Edinburgh is situated, after a thin covering of soil is removed, 

 consists entirely of sea sand very regularly stratified, with layers of 

 a black carbonaceous matter, in thin lamellae, interposed between 

 them. The height of this ground is about -10 feet above the pre- 

 sent level of the sea, yet in this sand fragments of sea shells have 

 at different times been found. These facts certainly prove either 

 a sinking of the level of the ocean, or an elevation of the land; 

 but the bed which 1 have described above appears to have been 

 deposited (luring a violent and temporary agitation of the sea, and 

 in all probability, does not belong to that --cries of geological pheno- 

 mena with which Von Buch and others have made us acquainted. 



The shells in this bed are in many eases broken ; but the frag- 

 ments are angular, and present no marks of continued attrition. In 

 this respect they prove themselves to have been deposited in a hurry, 

 and not to have been transposed from any distant quarter. 



Almost all the shells are large and thick, and must have belonged 

 to aged individuals. In examining the exuviae of the testaceous 

 usca thrown up by the sea (luring ordinary storms, we find 

 g and old shells blended together, but, in general, with a 

 ter proportion of the latter than of the former. In this bed 

 young shells appear. Tom fiist from the rocks, they have pro- 

 bably been reduced t" sand, while their aged sires have been raised 

 by violence from their beds, and shortly alter have been thrown up 

 in the state of confusion and disorder in which they arc at present 

 to be obi i rved. 



