142 
BATHYMETRICAL SURVEY OF 
colour), Ceratium hirundinella, Asplanchna, Anurcea cochleare, 
Anahcena were among the most abundant organisms. Many others 
were present in smaller numbers. 
Drummond Pond. — This is a shallow and nearly stagnant artificial 
pond, and many species were plentiful in the water. Daphnia 
lacustris was most numerous. Many males and females carrying 
ephippia were present. Other abundant species were C eriodaphnia 
(some with ephippia), Anurcea cochleare, Gonochilus, Asplanchna, 
Notops pygmceus. V olvox was scarce. The beautiful Rhizopod Difjfiugia 
corona was seen. 
The lochs of Strath Bran, though completely isolated one from 
another, and draining by different streams into the Bran, are fairly 
comparable one with another, being all, with the exception of Loch 
Freuchie, hill lochs of small size, lying at considerable elevations. 
Loch Freuchie. — This was one of the lochs where Holopedium for 
the time being abounded to the exclusion of everything else. Only a 
few individuals of Diaptomus gracilis (brown in colour) were seen. 
Hardly any small organisms were noticed. 
Loch Fender. — Life was abundant, but few species were present. 
The most numerous animals were Diaptomus (pale brown), Notholca 
longispina, Daphnia (parrot-shaped head), Bosmina longispina, and 
P eridinium tahulatum. Holopedium was not seen. 
Loch Hoil. — Life was very abundant. The commonest animals were 
Holopedium, Diaptomus gracilis, D. Wierzejskii (blue, red, or red and 
blue), Daphnia, and Asplanchna. 
Loch na Graige. — ^Animals of many species were present, but only 
four were plentiful — Diaptomus gracilis (blood-red), Bosmina ob- 
tusirostris (of large size), Daphnia lacustris (very large), and Gonochilus 
unicornis . 
Loch Kennard. — Some seven or eight species of animals were 
common in the loch, but Diaptomus predominated. D. gracilis and 
D . Wierzejskii were both present. Blood-red individuals of both species 
occurred, and D. Wierzejskii was also seen of the usual blue colour, or 
red and blue. Holopedium, Notholca longispina, and Asplanchna 
priodonta, and the somewhat rare crustacean L^atona setifera, were 
numerous. 
Loch Skiach. — The characteristic animals were Holopedium, 
Daplmia lacustris (very large), Bosmina ohtusirostris (very small, 
purple). Gammarus pulex of large size, and orange colour, was found. 
A few examples of Bosmina were large and brightly coloured, orange 
and purple. 
Loch Tag. — Comparing Loch Tay with Loch Rannoch, it is found 
that the plankton differs in several important particulars. Besides the 
common Diaptomus gracilis, there was another species, D. Wierzejskii, 
