ON THE PLANT REMAINS IN THE SCOTTISH PEAT MOSSES. 



49 



peat. Such features have been noted in the forest beds of other districts, and are 

 discussed later in describing the geographical distribution of the strata. 



The upper forest is again absent in the basin of the Bragor river, thick beds of 

 Scirpus and Eriophorum peat lying at that horizon instead of Pinus sylvestris. 



(c) Submerged Peat in Sandwick Bay, near Stornoway. — A deposit of peaty clay 

 underlaid by true peat occurs under mean high-water mark in Sandwick Bay to the east 

 of Stornoway. The deposit extends some distance along the beach, but it is impossible 

 to say how far it extends in a seaward direction. Whilst I was in the Lews, the tides 

 were not low enough to permit of sections being cut, but, owing to the kindness of Mr 

 D. Mackenzie of Stornoway, I received samples of all the layers from the surface to 

 the underlying rock, and an account of the sequence and thickness of the beds. 

 The surface lies about 6 or 7 feet under mean high-water mark, and the total depth of the 



Conglomerate 



Fig. 1 . —Submerged peat, Sandwick Bay. Lewis. (Vertical scale £ in. = l ft.) 



deposit is 4 feet 6 inches, underlaid by conglomerate. The position of the several 

 beds is illustrated in nV l. 



The peat at the base of the section is dry, hard, and shows but little structure. It 

 apparently consists chiefly of the debris of birch bark and the epidermis of Phragmites 

 communis rhizomes. The material is quite free from silt, and appears to have formed an 

 old land surface, and the peat is certainly not the accumulation of a bog, but represents 

 a forest bed, and it is clear from this that a depression of at least 1 2 feet has taken 

 place since the Lower Forestian. The sand immediately overlying the peat contains 

 many seeds of Zostera marina, and some traces of Sphagnum. 



4. The Mainland of Shetland. 



(Ordnance Survey— sheets 127, 128).— The Shetland Islands might be expected 

 to yield results of some value owing to their separation from the mainland by a 

 TRANS. ROY. SOC. EDIN., VOL. XLVI. PART I. (NO. 2). 7 



