MICROPALÆONTOLOGY OF POSTGLACIAL DEPOSITS. 489 
The deposit is 5 m. deep ; at first there is 200 cm. Eriophorum vaginatum 
peat successively passing into a dy-like substance (230 cm.), showing traces 
both of magnocaricetum peat and of carr peat. Beneath the dy-bed detritus- 
gyttja appears, resting on sand. In the lowest part of the gyttja is a thin 
laver of sand, 2 em. thick. 
Sample 9 shows a great resemblance to sample 9 from Firths Voe (moss 
No. 37); but if these samples actually are contemporaneous, then, either the 
formation of peat must have been more rapid in No. 34 than in No. 37, or 
erosion must have removed parts of the “ hill-peat ^ seen in No. 37 so as to 
leave the smooth surface of No. 34 intact. Solid wood, which made boring 
ditticult, was found 4 m. beneath the surface, but, curiously enough, the 
analysis of the sample from this layer resulted only in two pollen-grains, 
one of pine and one of lime. “Saliw” pollen has a great frequency, 
increasing from 40 per cent. in sample 5 to 100 per cent. in 8 and 115 per 
cent. in 9. Myriophyllum alterniflorum pollen occurs in samples 8 and 9 
(36, respectively 270 per cent.), and in the same samples also hairs of Cerato- 
phyllum have been seen. 
Pear Moss No. 55. 
Calluna-Empetrum moss with Scirpus erspitosus, Erica Tetralix, Eriophorum 
polystachion, Airopsis precoz, Rhacomitrium, Hypnum, and Sphagnum situated 
at the N.W. point of Petta Water, between the Mid Kame and the Voe- 
Sandwater Inn road, about 97 m. above sea-level. The section, 265 em. in 
depth, chiefly consisted of a Eriophorum vaginatum peat-like substance of 
which the lowest 110 em. were rich in twigs. In the loch amongst other 
plants Myriophyllum alterniflorum and Potamogeton polygoniflorus were seen, 
In order to get a control for the distribution of the pollen-grains in different 
parts of the mieroscopical preparations, a preparation was made from a sample 
53 em. above the sandy base of this moss, and examined as follows :——The 
number of pollen-grains was calculated separately for consecutive sections 
of the preparation analysed. The area of each section was 26:24 sq. mm. 
(232x082 mm.= the product of the length of the cover-glass and the 
diameter of the field of vision. Optical apparatus: a compensating eyepiece 
No. 6 and an apochromatic objective 8 mm.). 
| Alnus. Betula. Quercus. | Ulmus. Corylus. , “Salix.” 
| Section 1 ..... 002 31 — 4 — | 8 
|o» 2...) — 27 — | = = 2 
| | 
| po > — 19 1 | 1 — | 4 
Un 04 sese | L 24 — | — 1 | 8 
| " en 1 2 — | — Eu l | — 
| Total... — 4 122 TE 2 | 12 
| Percentage 3 | 955 | trace | 15 | (1:5) | (9) | 
| D | | i 
