(Gyeaaee) 
.—A further Contribution to the Freshwater Plankton of the Scottish Lochs. 
By W. West, F.L.S., and G. S. West, M.A. F.L.S. Communicated by 
Professor I. B. Batrour, F.R.S. (With Seven Plates.) 
(MS. received January 26, 1905, Read March 6, 1905. Issued separately June 15, 1905.) 
CONTENTS. 
PAGE PAGE 
I. Int oduction, . : . 477 | III. Systematic Account of the more important 
[. Detailed Account of the Bleaicon we the iow Alge of the Plankton, . : . 496 
. ‘investigated, c : - : 5 . 478 | IV. Gaul Remarks on Scottish ERptoplanicont . 509 
J. INTRODUCTION. 
On first investigation of Scottish plankton in 1901-2, although only tentative and 
what meagre, was sufticient to show that, as regards the phytoplankton, the lochs 
e west and north-west of Scotland were probably richer than any lakes previously 
ed. Owing to the extraordinary richness of the few collections then examined, it 
msidered eminently desirable that the investigation should be further extended. 
e have been enabled to do by means of a third successive grant from the Royal 
, and the present paper is one of the results of a visit to the north-west of Scot- 
July, August, and September, 1903. 
terial was collected from more than twenty of the lochs in Perth, Inverness, Ross, 
Outer Hebrides, and its examination has been most gratifying. The collections 
made in the ordinary manner by silken tow-nets, about 9 inches diameter at the 
1, and the material was mostly preserved in 4 p.c. formalin. It is to be regretted 
much of this material could not be examined in the living state, as there is every 
to believe from the preserved samples that some at least of the lochs were rich 
Heliozoa. 
In Perthshire, Loch Tay was investigated during the month of July along a great 
its length, and a number of collections were also made from the River Lochay. 
Inverness, six lochs were investigated during August, viz., L. Bairness, L. na 
Sgoilt, L. na Criche, L. Gorma, L. Morar, and L. Shiel. Of these, the two latter 
the best material. 
In Ross, material was collected during September from L. Luichart and L. Rosque. 
In Lewis, nine lochs were investigated during August. The plankton of most of 
se lochs was distinctly rich, especially that obtained from Loch Fadaghoda, which 
unrivalled for the abundance and diversity of its Desmid-flora. 
Harris, three lochs were examined, viz., L. Diracleet, L. a Mhorghain, and L. 
_ TRANS. ROY. SOc. EDIN., VOL. XLI. PART III. (NO. 21). 71 
