THE FRESH-WATER LOCHS OF SCOTLAND. 
353 
The long stretch of alluvium along the Amhainn-an t-Sratha Mhoir 
indicates that the lake has been silted up for about a mile above its 
present western limit. 
Loch an Tachdaidh and an Gead Loch . — These lochs lie in the 
bottom of the valley drained by the Garbh-uisge at Fait, which flows 
into Loch Monar, and are entirely surrounded by drift deposits of the 
later glaciation. All the small projections into these lakes are due to 
moraine heaps, arranged in such a way as to suggest that they are 
probably the terminal moraines of a lobe of ice that moved westwards 
towards the basin of the river Ling. 
LjocIi Galavie lies in one of the passes through which the ice escaped 
westwards from the Monar area during the period of confluent glaciers. 
Though immediately surrounded by moraines and peat, it is evidently 
in part a rock basin, as the rocky barrier formed of muscovite-biotite 
gneiss appears in the stream not far below the outlet of the lake. The 
deepest sounding is 84 feet. 
Loch Bunacharan and Loch cd Mhuilinn . — These lakes are situated 
in the valley of the Farrar about midway between Loch Monar and 
Struy. Their long axes seem to coincide generally with the strike of 
the crystalline schists. In the case of the former lake, its height above 
sea-level is 366 feet, its greatest depth 113 feet, and the position of the 
rocky barrier exposed in the stream about one-third of a mile below 
the outlet is about 360 feet. The surface level of Loch a’ Mhuilinn is 
417 feet, and the deepest sounding is 94 feet, and as it discharges over 
solid rock, it is evidently a small rock basin. There is a high terrace 
round Loch a’ Mhuilinn and on the south side of Loch Bunacharan at 
a level of 440 feet. 
Notes on the Biology of the Lochs of the Beauly Basin, 
By James Murray. 
The lochs of Beauly valley were surveyed in late autumn, during 
very severe weather, unfavourable for the study of biology. The lochs 
in Glen Affric were visited in a time of heavy floods, which raised the 
lochs several feet while we were working at them. Though the tow-nets 
were used, there was almost nothing got in them. The lochs appeared 
to be flushed and washed out by the spate, or else the animals had gone 
down to quieter water. 
Throughout the rest of the basin there was great uniformity, the 
ordinary universal limnetic Crustacea and Rotifers alone being present, 
with little call for remark. There was an entire absence of all the 
northern species of Dia'pto7nus^ and, although Desmids were fairly 
abundant in most of the lochs, there were none of the western species. 
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