22 DR. G. S. WEST ON THE ALG.E OF 
П. THE LITTORAL ALGA-FLORA (OR MICROPHYTIC BENTHOS). 
GENERAL NOTICE. 
Although careful investigations have been carried out on the phytoplankton 
of many lakes, more especially in Hurope and North America, very few 
detailed observations have been made on the benthos of these lakes with a 
view to discovering the relationships between the littoral species and those 
of limnetic habit. Such observations, to be of any real worth, necessarily 
demand a very extensive preliminary training in systematic work, and some 
of the recent publications exhibit only too clearly an insufficient. knowledge 
of the plants dealt with. In many cases this has resulted in conclusions 
having been put forward which are of very doubtful value. 
Among the weeds at the margins of the Yan Yean Reservoir, and 
especially in the vicinity of Honeysuckle Flat, there is a prolific Alga-flora 
which constitutes the microphytie part of the benthos and affords an 
interesting comparison with the phytoplankton. The collections were made 
periodically on the same day as the plankton-collections, and the variations 
of temperature, both of the water and the atmosphere, can be regarded as 
approximately the same as those tabulated in respect of the phytoplankton. 
The large weedy tract of the eastern bay of the lake, to which Mr. Hardy 
has given the name of Honeysuckle Flat, appears to be the principal recruit- 
ing ground for many species found in the plankton, and the periodie collec- 
tions from among the weeds were all made in this swampy area. Numerous 
wild fowl, such as ducks, coot, teal, black swans, herons, cormorants, etc., 
haunt this weedy flat, and deposit much excreta, some of which forms in the 
shallower parts a greasy scum on the surface, As the diet of these water-fowl 
is largely one of perch, blackfish, trout, ete., the mud of the reservoir must 
be considerably enriched by additional phosphates. The weed-collections 
were always made outside the feeding-ground of the water-fowl, generally 
from unnibbled weeds in from two to five feet of water. The coating of 
Algre was most evident on Triglochin procera, Potamogeton obtusus, Heleo- 
chams sphacelata, and Myriophyllum varüifolium ; and some of the larger 
species of the genus Staurastrum (especially S. leptacanthum and S. vic- 
toriense) were more than ordinarily prolific on the leaves of Vallisneria 
spiralis. 
As is commonly the case, and would naturally be expected, the algal 
species observed among the littoral macrophytes were considerably more 
numerous than those found in the plankton. 
