620 REV. THOMAS BROWN ON THE ARCTIC SHELL-CLAY 



4. The deposit in which the fossil shells occur. The upper portion of it con- 

 sists of layers of sand, with partings of finely triturated coal shale, the sand being 

 of an ochreous or deep brown colour. In this portion I observed no fossils. 

 Gradually, on passing downwards, the layers begin to get argillaceous till to- 

 wards the base, and in the eastern half of the section, the deposit passes into a 

 peculiarly stiff, tenacious, unstratified clay. It is here the shells occur, and in con- 

 siderable quantities. All the portions of the shells are in many cases beautifully 

 perfect, but they readily go to pieces when exposed to the air. 



Elie Inland Section. 



This was laid open in the railway cutting, beginning at a point to the east of 

 the railway station, and going west to the bridge beside the schoolhouse. It is 

 distant about the third of a mile from the preceding section, and showed, when 

 first fully laid open, the following series of deposits from above downwards : — 



Section III. 



Fig. 3. 



1. Blown sand of very considerable depth. All through it contains numerous 

 darker lines, showing former surfaces, and containing land shells, especially 

 the Succinea putris. Besides these there were intercalated, at four or five different 

 levels, distinct beds of peat, abode, the uppermost of which is 6 feet in depth. 

 They are full of land and fresh-water shells, to which I shall afterwards refer. 



2. A bed of peat, from 6 to 10 inches thick. The structure is markedly 

 different from that of the overlying peat beds, more earthy, and bearing a close 

 resemblance to No. 3 of the previous section. Like that it contained no shells. The 

 only organisms I detected in it were the roots of Equisetum, which, like those of 

 the Arundo in the peat of the shore, indicate a fresh-water origin. 



3. A deposit of gravel and sand, with portions of clay all arranged in layers, 

 which are nearly horizontal, but with a gentle dip eastwards, accommodating 

 themselves to the general lie of the ground. To the west of the schoolhouse, 

 where the ground slopes the other way, the inclination of these layers is also 

 reversed, showing that, when this deposit was laid down, the contours of the 

 country had the same outline as now. At some points the gravel was quite green, 

 from the debris of disintegrated basalts and greenstones, which have much the 

 appearance as if they had come from near M'Duff's cave, and if so, the current must 

 have flowed from the west. This whole deposit seems to be a portion of the 

 higher level sands and gravels which are found over the surface of the country, 



