626 REV. THOMAS BROWN ON THE ARCTIC SHELL-CLAY 



the sea than now. Here, in Largo Bay, a land surface, with rooted stumps of 

 trees, is seen passing out seaward at low-water mark. It may well have been 

 that the Britain of that time stood so high above the water as to have been con- 

 nected with the Continent. The only thing to be noted is, that if this were the 

 period of such connection, it must have been subsequent to the glacial epoch. At 

 the time of these submerged forests the Arundo grew abundantly, as now, in the 

 marsh, the willow put forth its catkins, and the hazel ripened its nuts in the 

 wood, and the whole flora, down even to the mosses, was the same as now. Thus 

 far the climate must have resembled the present, with no trace of glacial cold. 



IV. — High-level Gravel and Sand. 



This has been described in noticing the details of Section III., where it forms 

 bed No. 3. It should be distinguished from the second stage in this enumera- 

 tion. The latter lies only along the course of the stream, and is a river deposit, with 

 estuarine shells and no gravel, while this fourth stage consists of gravels and sands, 

 utterly without fossils, and scattered at considerable heights all over the sur- 

 face of the country. It was well displayed in the railway cutting. In one of the 

 layers of rather coarse gravel there were angular patches of fine sand ; and their 

 presence could only be explained by supposing that some sandy stratum had 

 been frozen, the current had gained access to it, broken it into fragments, which 

 in a frozen solid state had been transported along with the gravel, and deposited 

 where they now lie as angular masses of fine sand crumbling to the touch, 

 but having their angles sharply defined. If this be the right explanation, then 

 we have here the first indication of glacial cold in these deposits ; and, perhaps, 

 it points to the true origin of these masses of high level unfbssiliferous stratified 

 gravels and sands found over Scotland. They may be due to the floods attending 

 the breaking up of the glacial epoch. 



V.— The Arctic Shell-Clay. 

 Passing over the break in the series formerly referred to, we come to what is 

 the chief object of this paper, the period of the Arctic shell-clay. When my atten- 

 tion was first called to the subject in 1862, no deposit of Arctic fossil shells 

 had been found, either on the Forth or Tay. The first trace, indeed, had been 

 detected by Dr Fleming, Dr M'Bain, and the late Mr Bryson, but only two or 

 three specimens of the shells had been got, and they were held not to be indigenous. 

 The seeming absence of this fossil fauna from our eastern friths had led some 

 geologists of eminence to question the inferences drawn from those of the Clyde- 

 The discovery of the Elie shells, however, was at once decisive. Through the 

 obliging attention of Mr Carruthers of the British Museum, they were submitted 

 to Dr Otto Torell of Lund, who has himself dredged extensively in the Arctic 

 seas, is the author of an important work on the Shells of Spitzbergen, and is of 



