184 PROCEEDINGS OF THE GEOLOGICAL SOCIETX. [Jan. 11, 



and to the same author's notice of the one in Largo Bay in the Firth 

 of Forth*. Although Pleming's theory regarding these forest-beds 

 was, I consider, erroneous, yet his facts are always valuable, and he 

 entertained no doubt whatever as to the tree-roots in both of these 

 cases being in the place where they grew, and he enumerates Birch, 

 Hazel, and Alder as the prevailing species. 



In the valley of the Tay this bed of peat is known to occur along 

 a stretch of many miles, from the mouth of the Earn to Balmerino 

 in Fife. It forms the bed of the present estuary in many places, 

 and the tree-roots in it are frequently a source of annoyance to the 

 salmon-fishers in hauling their nets. Now this bed of peat, fuU of 

 remains of trees, passes right underneath the Carse, or old estuarine 

 mud of the Tay. It does not intermingle with this clay, but lies 

 clearly below it in a continuous stratum ; and those engaged in sink- 

 ing deep pits and wells near Abernethy are familiar with the fact 

 that, after passing through some twenty feet of this fine silty clay, 

 they get a bed of peat two or three feet thick, and beneath that no 

 Carse-clay is found. Mr, George Buist deserves the credit of having 

 clearly pointed out this in his memoir on the Geology of the south- 

 east of Perthshire, in the 13th vol. of the Transactions of the High- 

 land Society. I examined this peat-bed along the banks of some 

 small streams that join the Earn, near Abernethy, and found it to 

 be about 3 feet thick, in some places quite full of remains of 

 trees, and lying clearly below the whole mass of Carse-clay. Dr. 

 Dickie, who has examined for me some of the specimens I brought 

 home, reports the trees to be Birch and Alder. Below the peat there 

 is often a stratum of gravelly sand. The peat does not lie in dis- 

 jointed masses as if it had been drifted, but, so far as I saw, forms 

 a regular continuous bed of pretty uniform thickness and much 

 compressed. 



Near the farm of Invernethy pj "J.— Section near Ahernethy. 

 I traced its outer edge, where 

 it runs out apparently on the 

 surface of some laminated clay, 

 the boulder- earth emerging at 

 a short distance. Dr. Fleming 

 also states that at Largo Bay 

 the tree-stumps are rooted in 

 laminated brown clay. 



A bed of peat, occupying 1. Sand and gravel, 

 the same geological position, is ^- ^^^^, full of remains of Bireli and Alder, 

 found in some places beneath ^- <^^"^e-clay, or old estuarine mud of the 

 the Carse-clay or old estuarine 



mud of the Forth, as we learn from Mr. Blackadderf and Mr. Home 

 Drummond J. This peat stratum was said to contain remains of Birch 

 and Alder, together with seeds of a plant supposed to belong to the 

 genus Pedicularis. In the Carse-clay immediately above it, part of 



* Quart. Journ. of Science, Lit., and Art. vol. xxix. p. 21 (1830). 

 t Memoirs of the Wernerian Society, vol. v. p. 424. 

 X Ibid. vol. V. p. 440. 



