988 Proceedings of Royal Society of Edinburgh. [sess.. 
“Dredged the bottom of Loch ]S T ess for about 2 miles along the 
shore off Portclair Forest. In 30 feet to 60 feet of water no plants 
whatever were obtained : the bottom in many places consists of a 
stiff yellow clay, probably the same that is exposed at sections 
along the roadside from Fort- Augustus to Invermoriston. In 
sheltered bays Myriophyllum alterniflorum, DC ., occurs in water 
10 feet and even to 15 feet deep, often with an interrupted bottom 
carpet of Littorella lacustris, L., and Isoetes lacustris, L. In 
20 feet to 30 feet of water Nitella opaca, Ag ., is fairly abundant,, 
and usually covered with diatoms.” 
“Dredged about Cherry Island; at a depth of 15 feet to 20 feet- 
dense masses of Nitella opaca, A g., were obtained with Myrio- 
phyllum alterniflorum, DC. At 400 yards west of the island, 
Isoetes lacustris, L., forms a dense bottom carpet at a depth of 
14 feet to 16 feet. In water 35 feet to 50 feet outside Cherry 
Island, east and west, for some distance the bottom is of stiff 
yellow clay. No plants whatever were obtained from these 
depths.” 
“Dredged about the south-west end of Loch Ness from St 
Benedict’s Abbey towards Borlum and Glen Doe pier. Littorella 
lacustris, L., and Isoetes lacustris, L., sparingly in patches. Myrio- 
phyllum alterniflorum, DC., and Nitella opaca, Ag., fairly abundant 
in places from 5 feet to 12 feet deep ; beyond this depth N. opaca 
and Fontinalis antipyretica, L., only ; form scattered growth to 30 
feet and an occasional plant in even deeper water. Beyond 40 feet 
no plants were obtained. The bottom here is mostly gravel down 
to 30 feet or 40 feet; in deeper water mud obtains. This seems to 
imply the action of the waves being sufficient at that depth to 
prevent a mud deposit. The Nitella here were heavily invested 
with diatoms, filamentous algge were scarce, young plants of 
Batrachospermum moniliforme, Roth., were common on some of 
the Nitella, but no large specimens were procured from the deep 
water, although they are abundant and grow to a full sixe in 
shallow water at the estuary of the river Tarff.” 
“ At Urquhart Bay abundant and varied vegetation was obtained 
to a depth of 15 feet ; exceeding this depth, Nitella opaca occurs to 
30 feet. No plants were found in deeper water. The bottom is 
firm and sandy to 20 feet or 25 feet ; beyond this depth mud occurs. 
