154 
Proceedings of the Royal Society of Edinburgh. [Sess. 
gonum and Ranunculus are also abundant at other parts of the loch. 
Zannichellia palustris, var. brachystemon, occurs in extraordinary quantity 
on the deep black mud at the west side, whilst Myriophylluin spicatum is 
so plentiful in some places, particularly on the east side, that the surface of 
the water appears crimson with its flowers. Callitriche autumnalis occurs 
chiefly in small patches a yard or less across, but in a few places considerable 
areas of the sandy bottom are covered with it. Lemna trisulca is extremely 
abundant in shallow water, especially at the north side near the village. 
Large masses of Cladophora flavescens and Enteromorpha intestinalis were 
floating about in many places ; indeed, I have only seen such a prodigious 
quantity of the last mentioned at one other place in Scotland, namely, at 
Duddingston Loch, near Edinburgh. In some places a species of Nostoc was 
abundant, floating in masses amongst the vegetation of the margin. A 
single specimen of Hippuris vulgaris was gathered here, having the nodes 
in the form of a continuous spiral from base to apex. Considering the 
shallowness of the loch and the other apparently favourable conditions, it 
seems astonishing that the reeds which grow so luxuriantly at the margin, 
particularly Scirpus lacustris, Phragmites communis, and Equisetum limosum, 
have not overgrown it almost completely. 
Besides those already mentioned, the following plants were plentiful at 
this loch : — Chara aspera and its var. capillata, Potamogeton crispus, P. 
perfoliatus, P. obtusifolius, Lemna minor, Caltha palustris, Sium angusti- 
folium, Comarum palustre, Epilobium tetragonum, Mimulus Langsdorffli, 
Myosotis palustris, Veronica scutellata, Mentha aquatica, M. sativa, 
Equisetum arvense, E. palustre, Ranunculus Flammula, Juncus acutiflorus 
and J. efiusus. There are a few common bog mosses, but such are not 
abundant, as favourable situations are scarce. 
Halton Reservoir is a small, irregularly shaped sheet of water situated 
about 2 miles north of Largo. It has been formed by the widening of 
the natural gorge of the Halton Burn and by the construction of a dam at 
the lower end. At the time of my visit the water had fallen about 12 
feet below the full water level, leaving upon the exposed mud the remains 
of a number of aquatic plants. Some of these were growing in terrestrial 
form upon the mud, e.g. Myriophylluin spicatum, Polygonum amphibium, 
Ranunculus peltatus, Potamogeton natans, Callitriche stagnalis, etc. In 
some places the mud was thickly covered with dead remains of Chara 
fragilis, which is extremely abundant there. A large quantity of the same 
species was still flourishing in the water, which under conditions of normal 
water level would be at a depth of about 14 feet. Gnaphalium uliginosum 
is very abundant, and forms a sward upon the sides near the full water level . 
