6 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. uxix. 
and Urucigenia irregularis, Wille, from several lochs in ‘the 
Shetlands. The latter is of special interest, as it occurs in 
the Norwegian plankton. Very large forms of Amphiplewra 
pellucida, Kitz, were observed in some oi the collections, 
individuals attaining two or three times the usual size of- 
this Diatom. Two undescribed species of Staurastrwm oc- 
curred in quantity: a very prettily marked species—+S*? 
boreale, sp. n.—tfrom Loch Asta, and St. affine, sp. n., from 
Loch Brindister and Neugles Water. ‘St. Manfeldtii, Delp. 
was not uncommon, and in Loch Sandy it was in enormous 
abundance. 
One form of Xanthidium antilopeum (Bréb.), Kiitz, eich 
appears to be a feature of the plankton of the English Lake 
District, of Scotland, and the Outer Hebrides, and which 
occurred in quantity from the Shetlands, we have named 
X. antilopeum, var. depauperatum. , 
Quite recently Bérgesen and Ostenfeld? have reported on 
some plankton from the Faerées, and of the 52 species of 
alge they record, 28 occur in the plankton of the Shetlands. 
A number of the Peridiniexz were abundant, and some 
long-spined forms of Cerativm hirvndinella were observed: 
Rhizopods were by no means uncommon, and the Rotifers 
Anures cochlearis, A. aculeata, and Notholea longispina, were 
abundant. Mallomonas acaroides occurred in immense quan- 
tity in Loch Sandy, and large numbers of Die were in 
the plankton of Loch Trebister. 
The description of these plankton-collections is tabulated; 
the last column being reserved for Bérgesen and Ostenfeld’s 
records from the Faerdes. This is inserted for direct 
comparison. sara a 
1 F. Borgesen and C. H. (Ostenield, “ Phytoplankton of Lakes in ees 
Faerées,” “ Bot. of Faerdes,” Copenhagen, 1902. ; 
