196 
BATHYMETRICAL SURVEY OF 
the south shore of Loch Ej3ort, between the Oban nam Fiadh basin and 
Loch Obisary. It is nearly one-third of a mile long and one-eighth of 
a mile in greatest breadth. It is one of the highest lochs surveyed, being 
27*95 feet above sea-level on June 7, 1904. It is very shallow, the 
maximum depth being 9 feet. It drains north into Loch Eport by a 
short burn. 
The Ohan nam Fiadh JE?«sw.“-This comprises seven lochs, of which 
the lowest, Oban nam Fiadh, is purely tidal ; while Loch Caravat, the 
largest loch of this basin, is very slightly brackish. Two chains of lochs 
connect with Loch Oban nam Fiadh. On the east Loch na Coinnich, 
communicating with Loch na Ceithir-Eileana, and on the south Loch 
Caravat. West from Loch Caravat lies Loch an lasgaich ; east from it 
Loch Tc Colla, connected with which is Loch an t-Seasgain. 
! Loch Ohan nam Fiadh (see Plate LXXV.). — This loch is of unusual form 
among the lochs of North List. It is elongate and narrow, over a mile 
long by a quarter of a mile in greatest breadth, and with a mean breadth 
of one-eighth of a mile, covering an area of about 92 acres. It is divided 
into three portions by narrows. The main part is of oblong form, its axis, 
east and west, two-thirds of a mile long. There are several small islands, 
one in the centre of the loch. The bottom is uniform, 5 or 6 feet in depth, 
but with two dej)ressions of 10 feet. The middle and upper portions are 
small, and 4 to 5 feet in depth. They are separated by a low island, and 
the whole channel here is grown up with reeds. The stream from Loch 
Caravat enters the U23per basin. The shores are of rock. 
The loch is interesting from the transition it shows from salt to fresh 
water, and the corresponding difference in the fauna and flora of the upper 
and lower basins. The lower part is jourely tidal. If not filled by all 
ordinary tides, it is, at any rate, so frequently filled as to enable sea-weeds 
to grow and marine animals to live. Yet fresh- water plants also grow in 
this 2 ^art, and mussels are found adhering to these. The very narrow 
channel and the dense growth of Phragmites prevent the tides from having 
much effect on the upper 2 )ortion in summer. Here the water tastes 
almost fresh, and such fresh-water Crustacea as Holopedium are found. 
Yet high tides must raise this part considerably, as Loch Caravat, at the 
time of our visit 2 feet higher, is filled through it. The temperature at 
the surface was 68°*0 Fahr,, and at 6 feet 66°*8, on June 7, 1904. 
Loch Caravat (see Plate LXXV.).— Loch Caravat is the second deepest 
among the larger lochs of the island, though the little Loch a’ Ghlinne- 
Dorcha is somewhat deeper. In general form it resembles the letter H, 
there being two narrow j)ortions running east and west, connected by 
a narrow channel running north and south. In these circumstances it is 
difiicult to define length and breadth ; a line drawn from the west end of 
