TRANSACTIONS OF SECTION C. 1035 
worked out, in deposits partly levelled out by the sea, according to the laws of river 
terracing under the accelerating influences of a falling sea-level. The processes of 
automatic river terracing are beautifully exemplified within the district mapped, in 
the deep lobe-shaped curve of the river just before it enters the sea. The terraces 
have been added one after another to the point of the lobe of land thus surrounded, 
which is known as Oen. 
9. The Parallel Roads of Lochaber. By James MEtvin. 
These singular-looking lines, resembling in the distance water-races or roads 
traced along the mountain sides of three glens in Lochaber, have hitherto proved a 
puzzle to the learned and unlearned. 
The theories submitted to account for their origin are open to grave objections, 
and all of them, save that of their being the margins of lakes held in by the ice of 
glaciers which flowed down the corries from the lofty mountains, have generally 
been given up. 
This last, when carefully considered and looked at from different points of view 
in the district itself, seems open to serious objections. In the first place, it neces~ 
sitates the existence of great glaciers in the lower portions of the glens with the 
water of lakes in the higher. It further necessitates the cessation of certain of 
these glaciers in Glen Spean, over perhaps nine-tenths of the district formerly pro- 
ducing them, and their retention in one-ninth of the surface from which they had 
previously flowed. 
TASMAN VALLEY, MOUNT COOK,NEW ZEALAND. 
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SECTION AND TERRACE IN LOWER VALLEY. 
(Methed by which the Glacier forms Terraces somewhat similar, perhaps 
exactly similar, to those of the Lower Tasman Valley.—Page 200, 
Green’s ‘ High Alps of Queensland.’) 
Those corries and opener glens, such as the Gulbein, the Treig, and the Laire 
which it is said supplied the ice-barriers when the upper roads in Glen Roy were . 
being formed, issumg as they do from 100 square miles of mountain country, the 
peaks of which rise to 3,658 feet, according to the requirements of the ice-dam 
supporters, must become barren. These glaciers must shrink up, without any other 
reason being assiened than the necessity of their doing so to enable the supporters 
of the ice-dam to prove their case. 
While this large extent of previously ice-producing country ceases to furnish 
any more ice to the Spean valley, one solitary glen, the Cour, drawing a supply 
from about eleven square miles, is allowed to maintain all its original ice-producmg 
