342 
Proceedings of the Eoyal Society of Edinburgh. [Sess. 
2. The layer of whitish marl occurred chiefly on the western side of the 
floor of the cave (see fig. 6). The remains obtained from it consist almost 
wholly of the shells of small Pupa-like land snails, pointing to a long 
period when, with the exception of a few splinters, only the limestone- 
loving land shells dropped from the walls and roof of the cave. 
1. The thin peaty layer at the top is composed almost wholly of excre- 
ment of sheep. In recent years it has been the custom during severe snow- 
storms to drive the sheep into this part of the valley to enable them to find 
shelter in the caves of Crea^ nan Uamh. 
Among the mammals obtained from this bone-cave the Arctic Lemming 
is of special interest because the remains of this animal were found by the 
late Mr James Bennie in the arctic plant bed of the ancient lake at Corstor- 
phine, near Edinburgh. At the latter locality the paleontological evidence 
indicates that the deposit is probably of late glacial age. 
In his published description of this old lake deposit Mr Bennie did not 
record his discovery of the jaw-bone of the Lemming which had been 
determined by Mr E. T. Newton, F.R.S. Special thanks are due to Mr 
William Evans, F.R.S. E.,* for calling attention to this discovery and obtain- 
ing permission from the Geological Survey to have the jaw-bone re-examined 
by Mr Newton. He reported : “I do not think there can be any doubt as 
to the larger jaw belonging to a Lemming, and it is closely allied to the 
Arctic Lemming, which is now called Dicrostonyx torquatus ; but being 
imperfect one cannot speak with certainty as to the species.” 
The arctic plant bed at Corstorphine occurs in the lower part of a suc- 
cession of lacustrine deposits filling a silted-up lake. The seeds and leaves 
collected by Mr Bennie were determined by the late Mr Clement Reid, F.R.S . y 
who stated that the vegetation consists mainly of dwarf willow and birch 
with a few herbaceous plants belonging to species still living within the 
Arctic Circle.-)- Amongst the arctic species are dwarf birch ( Betula nana), 
willows (Salix polaris, S. herbacea, S. reticulata ), the white dry as (Dry as 
octopetala), and Oxyria digyna. From the evidence of the plants Mr Reid 
inferred that the deposit is probably of late glacial age.J This conclusion 
is confirmed by the occurrence in the plant bed of remains of Lepidurus 
(Apus) glacialis, a phyllopod now found living only in the freshwater 
lakes of Greenland and Spitsbergen. The discovery of the remains of the 
Arctic Lemming in the same deposit is another link in the chain of evidence 
indicating the climatic conditions which then prevailed in Scotland. 
* Proc. Roy. Phys. Soc. (1906), vol. xvi, part 8 ; also The Scot. Naturalist , No. 17, May 
1913, p. 97. 
f Brit. Assoc. Rep., 1892, p. 716. f Origin of the British Flora , 1899, p. 62. 
