LAKES IN EELATION TO GEOLOGICAL FEATURES 491 
the Lome plateau. The valley in which they lie was evidently an 
arm of the sea during the stage of the 100-ft. beach^ since a fringe 
of that l)each is traceable at intervals round the lakes. Fluvio- 
glacial deposits^ due to melt-water from the lobe of ice which passed 
down the Lonan valley into Loch Nell, occur along the western end 
of the chain of lakes. 
Black (Ryan basin). — Kettle-hole in fluvio-glacial gravels of 100-ft. 
beach ; has been continuous with the White Loch, from which it is 
now disjoined by the delta of Sheuchan Burn. 
Black (Tay basin). — Kettle-hole on pass between Lindores and the 
Howe of Fife. 
Blairs. — Kettle-hole in fluvio-glacial deposits. 
BoARDHOusE. — Hollow in flagstones of Middle Old Red Sandstone age, 
ponded by drift. 
BoDAVAT. — Rock-basin in Lewisian Gneiss. 
BoGTON. — Partly a rock-basin in Coal Measures, and partly drift-dammed ; 
now much silted up by the river Doon, which flows through it. 
Borralan.— Vol. n. Part I. p. I9I. 
BosQUOY. — Resting on Middle Old Red flagstones, and ponded by drift. 
Bradan. — Drift-dammed lake lying on Lower Silurian greywackes and 
shales. 
Braigh Horrisdale. — Rock-basin partly in Lewisian Gneiss and partly 
in Torridonian rocks. 
Bran. — One of a group of small rock-basins on a floor of Old Red Sand- 
stone and crystalline schists along the south-east side of Loch Ness. 
At Loch Bran the platform is cut in schists from 6OO to 700 feet 
above the level of Loch Ness. The streams draining these lochs, of 
which the Foyers is one, occupy hanging valleys relatively to Loch 
Ness, towards which they descend by a succession of rapids and 
waterfalls. 
Breac, nam. — Irregularly shaped rock-basin in Lewisian Gneiss, with 
numerous islands and uneven floor. 
Breac Dearga, nam. — Rock-basin in hollow traversing the Middle Old 
Red Sandstone rocks on the northern face of Meallfourvounie. 
Breaclaich. — ^ Rock-basin. 
Broom. — ^Drift-dammed. 
Brora. — Valley rock-basin in granulitic schists where the valley becomes 
constricted between the Middle Old Red Conglomerate hills, Ben 
Smeorail (1592 feet) on the north and Ben Horn (1708 feet) on the 
south. Four separate basins occur on the floor of the lake. 
Brough. — Resting on Old Red Sandstone and ponded by drift. 
Brouster. — Chain of lakes in valley carved out of altered Old Red 
Sandstone strata. 
Brow. — In drift, separated from Loch Spiggie by delta of Burn of Hill. 
Bruadale. — Upper part of Loch Urrahag. 
Buaille, a'. — Rock-basin in Lewisian Gneiss. 
