ON THE PLANT REMAINS IN THE SCOTTISH PEAT MOSSES. 341 



on Ben Aricaiter in the Valley district, at 180 feet above O.D. The peat is here only 

 about 5 feet in depth, and the surface is channelled into peat-hags. The following beds 

 were met with : — 



1. Scirpus, Eriophorum, Sphagnum, and Racomitrium peat. 



2. A thin layer containing abundant Phragmites. 



3. Small Betula alba, L., none of the stems being more than 2 or 3 inches in 

 diameter. 



4. Black hard peat, separated distinctly from the overlying layer, and containing 

 much compressed birch bark. 



Borings were then made over an area of four or five square miles, lying at about the 

 same altitude, and these showed the same sequence of beds. In all cases the same 

 separation of the birch zone appeared, the upper containing well-preserved wood and 

 the lower containing only birch bark. 



Sections were also made on Ben Aricaiter and the moorland to the west, at altitudes 

 ranging from 250-400 feet. The peat here is deeper, averaging about 9-12 feet, and 

 shows the following : — 



1. Scirpus, Eriophorum, Sphagnum, and Calluna peat. 



2. Calluna becomes very abundant, and forms a zone some 3 or 4 inches in 

 thickness. 



3. Phragmites peat, with abundant Menyanthes trifoliata, L., towards the base. 

 This peat rests upon angular stones, micaceous sand, and coarse grit. Numerous 



horizontal bands of grey clay occur towards the base of the peat, with occasional patches 

 of grit, showing that flooding was frequent during the deposition of these older beds. 



Lower down, towards Loch Steaphain, Betula alba of fairly large size (10 inches to 

 18 inches diameter) is present at the same horizon in the peat as the Calluna zone 

 described from the last section. This is the only evidence of the existence of an 

 upper forest-bed met with in the Hebrides ; but in the absence of any other well-marked 

 datum line, the comparison of this peat with that in the Eastern Highlands cannot be 

 made. 



Caithness. 



(One-inch Ordnance Survey — sheet 115.) — The stretch of country for some distance 

 on each side of the Caithness-shire-Sutherlandshire boundary is, with the exception of 

 a few small areas, entirely covered with deep peat deposits. The peat runs north-east 

 into Caithness-shire, towards Thurso and Wick ; and although, near these places, it has 

 been much worked in past times for fuel, yet westwards and southwards it forms an 

 almost unbroken covering on the flat moorlands and isolated hills like Ben G-riam Mor 

 and Ben Oriam Beg. The area so covered may be put roughly at about 24 miles 

 from north to south and 40 miles from east to west. It was found possible last 

 year to touch only a small part of this area, the district chosen being westward from the 

 Highland Railway between Altnabreac station and Scotscalder station. Although the 



