288 Part I1T.—Twelfth Annual Report 
‘and is very pure and transparent. There are large quantities of fresh- 
‘water shrimps (Gammarus pulex) all over the loch,—among the gravel, 
‘under stones, and sticking to the weeds. leeches are also very 
‘abundant, but I do not find fly-life very plentiful. There are a great 
‘ quantity of curious gelatinous substances adhering to stones and lying 
‘about in the gravel shoals which I never noticed before in any lake.” 
The crustacean fauna of the little loch, to judge from the tow-net 
gatherings sent to me, is evidently very abundant and very interesting. 
One of the Copepods from this loch—Diaptomus serricornis—is new to 
the British Islands. Since the discovery of Diaptomus serricornis, Lillje- 
borg, in Loch Mullach Corrie it has been ascertained that the same species 
was found by Mr David Robertson of Millport many years ago (1867) in 
a pond near Lerwick, Shetland, but had remained unnoticed in print till the 
discovery of the species in the Sutherlandshire loch. A variety of Daphnia 
pulex (Linné), having the distal half of the hairs on the antennules and 
also the posterior spine of a black colour, was frequent in the tow-net 
gatherings from Loch Mullach Corrie; I propose to call this variety 
nigrispinosa. The ‘shrimp’ (Gammarus pulex, Linné) which Mr Caine 
describes as abundant in the loch is an evidence of the purity of the water. 
This is a species that can only thrive in water that is more or less pure ; 
if transferred to impure water it very soon sickens and dies. The leeches, 
referred to in the description of the loch, belong to the genus Hexmopsis 
(the horse-leech) which is found in ponds ‘and ditches all over the country. 
Seven stomachs of trout from this loch were sent by Mr Caine and they 
all contained Gammarus in greater or fewer numbers, in one or two of 
the stomachs there were alone with the Gammarus a few insects, or 
portions of insects, chiefly of the Phryganeide. The plants that were for- 
warded comprised specimens of a species of Chara; of Fontinalis antepyre- 
ica, —& moss common in some fresh-water streams and shallow lakes ; 
of Lnttorella lacustris ; of Menyanthes trifoliata (the Bogbean) ; of 
Millifolium spicatum (water-milfoil) ; and a species of Potamogeton, or 
pond-weed. Among the animal organisms specimens of the curious 
little so-called ‘ water-bears’ (Tardigrada) were observed specimens of 
insects chiefly of the Phryganeide and Coleoptera, specimens of the 
Hemopsis, already referred to, and the following crustacea were also 
obtained. 
AMPHIPODA. 
Gammarus pulex (Linné). Abundant, 
CoPEPoDA. 
Diaptomus serricornis, Lilljeborg. Frequent, 
Cyclops signatus, Koch. Few. 
»  thomasi, Forbes. Few. 
5  virides (Jurine). Few. 
»  serrulatus, Fischer. Few. 
» affinis, G. O. Sars. Few. 
Attheyella,crassa (G, O. Sars). Few. 
CLADOOERA, 
Daphnia pulex (Linné). Frequent 
» var. nigrispinosa, Frequent. 
Bosmina longtrostris (Miiller). Frequent, 
Alonopsis elongata, G. O. Sars. — Few. - 
Alona quadrangularis (Miller). Few. 
Graptoleberis*testudinaria (Fischer), Few, 
Chydorus spheericus (Miller). Frequent, 
