40 
BATHYMETRICAL SURVEY OF 
LOCHS OF THE GRUINAEH BASIN. 
Within tRis basin eight lochs were sounded by the Lake Survey, viz. 
Lochs na Sheallag, Fionn, Dubh, Beannach, na Moine Buige, Eileach 
Mhic’ille Riabhaicb, Fada, and na Beiste. The drainage basin under 
consideration (see Index Maj), Fig. 3) extends from the mouth of Gruinard 
bay (between Stattic Point on the east and Creag an Eilean on the west) 
to the heights of Beinn Tarsuinn, Mullach Coire Mhic Fhearchair, and 
Beinn Bheag, and includes numerous small lochs which could not be 
surveyed for lack of boats. As measured by the planimeter on the 1-inch 
Ordnance Survey maps the total area of this basin is about 117 square 
miles, of which considerably more than one-half, or over 6 6^ square miles, 
drain into the lochs under consideration, as will be seen in the summary 
table. Loch na Sheallag flows directly into Gruinard bay by the river 
Gruinard, as does Loch Fada by the Allt Bad an Luig, and Loch na 
Beiste by the Allt Udrigill, while the remaining lochs mentioned form 
a connected series, whose waters are carried into Gruinard bay by the 
Little Gruinard river. Loch Dubh adjoining the head of Loch Fionn, 
Lochan Beannach flowing into Loch Fionn about midway down the western 
shore, Loch na Moine Buige flowing in at the head of Loch Fionn, while 
Loch Eileach Mhic’ille Eiabhaich carries the outflow from Loch Fionn 
into the Little Gruinard river. 
Loch na Sheallag (see Plate XVI.). — Loch na Sheallag is situated 
about 9 miles to the north-east of Loch Maree, amid wild and magni- 
ficent scenery, the head of the loch lying between the heights of An 
Teallach (Bidein a’ Ghlas Thuill — 3483 feet, and Sgurr Fiona — 3474 
feet ) on the north-east, and of Beinn Dearg — 2974 feet — on the south- 
west. It contains salmon, sea trout, river trout, and char, but the fishing 
is preserved. The loch trends in a south-east and north-west direction, 
and is 3| miles in length. It is broadest towards the south-eastern 
(inflow) end, where the maximum width of over two-thirds of a mile 
occurs, narrowing gradually towards the outflow end. Its waters cover 
an area of about 876 acres, or over 1| square miles, and it drains an area 
27 times greater — an area of about 37 square miles. The maximum depth 
of 217 feet was observed in the wider part of the loch, about a mile from 
the south-east end. The volume of water is estimated at 3948 millions 
