io8 
Notes and Comments . 
most marked peculiarity is that they consist of two distinct 
kinds of boulder-clay and gravel, the upper series being 
derived from the east and the lower from the west and north- 
west. This great disparity in the nature of their rock con- 
tents induced me. in 1S96. to regard them as belonging to two 
distinct epochs of glaciation. I am now, however, of the 
opinion that they all belong to one great period of ice advance 
and retreat, which was probably marked by considerable 
but minor oscillations of the ice-front ; for although the area 
might appear to be anything but a marginal region of the ice- 
flow. it really occupies such a position.’ 
SCANDINAVIAN AND BRITISH ICE. 
He concludes that ‘ Britain, being near the edge of the con- 
tinental shelf, would respond more readily to temperature 
changes than the Scandinavian ice-sheet to the north-east. 
It may therefore have happened that the British ice was on 
the wane long before the Scandinavian ice reached its greatest 
extension. Temporary changes of temperature would also 
tend to affect the margins of the ice-sheet rather than the 
centre of the area of dispersion. It thus seems to have come 
about that the maximum extension of different portions of 
the ice-margin occurred at different times, and that tem- 
porary slight ameliorations of climate affected the margins 
of the ice-sheet supplied by the British mountains more than 
they did the marginal portions fed by the Scandinavian ice. 
If this reading of what took place be correct, we must not 
regard a map showing the ground which had been covered 
by the ice-sheet at maximum extension as indicating the actual 
extent of the ground covered by ice at any one time, for it 
would appear that when the North Sea ice reached the neigh- 
bourhood of London the glaciers from the British mountains 
were already on the wane.’ It will be observed that this is 
the opposite of Mr. Lamplugh’s view : he considered that the 
waxing of the British ice caused the North Sea ice to wane. 
A PALAEOLITHIC SKETCH. 
At a meeting of the London Geological Society on 7th 
March Dr. A. Smith- Woodward exhibited and described a 
fragment of bone bearing an incised drawing of the fore-part 
of a horse, in the style of drawings already well known from 
several habitations of Palaeolithic Man. The specimen was 
found by schoolboys in an old mound of debris from a quarry 
in the Inferior Oolite near Sherborne, Dorset, Nothing is 
known of the circumstances under which it originally occurred ; 
but the situation of the quarry is in a small dry valley, on a 
steep slope facing south-westwards, and the bone may perhaps 
have been removed with the remains of a rock-shelter. No 
Naturalist, 
