254 THE FRESH-WATER LOCHS OF SCOTLAND 
ing terrestrial forms of Littorella lacustris, an aquatic form of Bryum 
pallens, Riccia crystallina, Potamogeton obtusifolius, var. fluitans, 
Myriophyllum spicatum and M. alternifiorum growing together, 
Jnncus glaucus, Veronica scutellata, etc. 
Otterston Loch is a small sheet of water two miles west of 
Aberdour. It is closed in by low hills, and is entirely surrounded by 
luxuriant deciduous trees, which also cover a small island in the 
middle. The water is not peaty and, although clear, it has a dead, 
stagnant appearance. The loch is of an ornamental nature, and 
Otterston House stands upon its north side, whilst the public road 
borders it on the north-east. Except on the west side, where there 
is an extensive and treacherous bog, the loch is bordered nearlv everv- 
where by low walls or grassy banks, so that there is practically no 
shore, but in several places marsh vegetation overgrows the banks. 
At the west end the mud at the bottom is deep, black, and fetid ; 
there is much less mud at the east end, where some parts of the 
margin are sandy, or a narrow zone of stones may even occur. 
Ceratophyllum demersum is so abundant that the loch is almost 
choked with it, and in the summer when the plants are at the surface, 
the manipulation of a boat over the water is a matter of some difficulty. 
Doubtless many plants that otherwise would thrive in this loch are 
excluded by the Ceratophyllum. It does not, however, appear to be 
able to hold its own in the marginal zone against a large association of 
Polygonum amphibium which grows there. Considerable portions of the 
bog at the west end are covered with associations of Menyanthes tri- 
foliata, Ranunculus Lingua, and Carex paniculata. The last-mentioned 
grows in large tussocks, and dominates the greater portion of the 
bog. A considerable nmnber of other plants grow at this loch, the 
most uncommon species being: — Zannichellia palustris, Lemna trisulca, 
Cicuta virosa, and Scirpus sylvatica near the loch (PI. I. and II.). 
Loch Fitty is situated amidst a mining and agricultural district, 
three miles west of Cowdenbeath. It is a mile long by one-third of a 
mile wide. The water is clear, but it has a flat, dead appearance, 
especially so in autumn when the vegetation, particularly Chara, is 
decomposing. The shore at the north side is stony or gravelly, and 
almost destitute of marsh plants. At the south side a portion of the 
shore is composed of shale, which has been thrown out from an adjacent 
mine, and a number of aquatic plants occur in the pools and little bays 
formed by the irregularities of this substance. At other places upon 
this side of the loch the shore is gravelly or sandy, and bears more 
plants than is the case upon the opposite side. At the west end the 
affluent enters the loch, previous to which it has a very sinuous course 
for about a mile through an alluvial flat consisting of agricultural or 
meadow-land, doubtless at one time covered by the water of the loch. 
