792 B. N. PEACH AND J. HORNE ON THE 
the Skerries. For these various reasons, therefore, we are justified 
in inferring that the glaciation of these outlying islets is due 
to the action of an ice-sheet originating far beyond the sphere of 
Shetland. 
On the eastern seaboard of Northmavine, in the Mainland, between 
Ollaberry and North Rooe, the general trend of the ice-markings is 
in a south-westerly direction. On the north shore of North Rooe Bay 
two sets of striz were observed—one pointing 8. 40° W., belonging 
to the primary glaciation; the other 8. 30° K., produced by later 
glaciers moving down the bay. Near Fethaland Point two sets of 
strigz were observed, which clearly prove the general movement of 
the ice during the primary glaciation, and at the same time a 
separate movement of the lower portions of the mass caused by an 
undertow. On the headland north of the fishing-station the striz 
run N.W. and N. 20° W.; while on the south side of the bay, about 
a mile from the fishing-station, the markings on the cliff-heads 
point N. 6° W., N. 10° E., N. 20° W., indicating a varying movement 
in a northerly direction. On ascending the polished slope which 
overlooks the foregoing examples, the direction is 8. 10°-35° W. 
This divergence is readily accounted for by supposing that the lower 
current moved in a north and north-west direction, while on the 
slopes of the ridge the upper current moved towards the south-west 
in harmony with the general moyement along the eastern seaboard 
of the Mainland. 
Again, in the upper part of Roeness Voe, the striz point W. and 
W. 10° N.; but on descending the sea-loch they swing round to the 
north-west, the instances near the mouth of the yvoe trending 
N. 20°-28° W. The same northing of the striz is splendidly seen 
on the area occupied by the interbedded volcanic rocks between 
Braewick Bay and Hamna Voe, the direction varying from N.20° W. 
to N.W. 
Along the highroad from Ollaberry to Mavis Grind, numerous 
instances were observed which likewise indicate a passage of ice 
from the North Sea towards the Atlantic. On reaching Sulem Voe 
from the north, the eye at once fixes on a large roche moutonnée of 
diorite, which rises to a height of 200 feet above the sea-loch, and the 
surface of which is finely polished and striated, the markings pointing 
W.5°S. And so, also, the narrow neck of land at Mavis Grind 
is similarly grooved; indeed, over the whole of the district round 
Hagrister and Islesburgh and north of Magnusetter Voe, the ice- 
worn aspect of the hills is very apparent, the smooth slopes looking 
to the east, while the rough slopes face the west, indicating the 
direction from which the ice came. 
On the eastern shores of the districts of Nesting, Lunnasting, and 
Delting there is no lack of evidence regarding the glaciation, as strize 
are plentiful, and in certain areas there is but a scanty covering of 
peat and herbage. It is difficult to convey an adequate impression 
of the singularly bare and mamillated appearance of the tract 
of ground which forms the peninsular headlands of Lunnasting. 
Bare dome-shaped hills, dotted all over with lochs, occur in the 
