} 
of the Fishery Board for Scotland. 273 
Candona candida (Miiller). Generally distributed, frequent. 
Ks lactea, Baird. Generally distributed, frequent. 
is kingsleiit, Brady and Robertson. North shore, not common. 
» pubescens (Koch), Frequent and generally distributed. 
Ilyocypris gibba (Miller). North side frequent ; south side rare. 
Cytheridea lacustris (G. O. Sars). Frequent all over the bottom of the loch. 
Limnicythere sancti-patrici,. Brady and Robertson. Generally distributed, 
common. 
on inopinata, Baird. Generally distributed, not common. 
CLADOCERA. 
Daphnella brachyura (Lievin). Generally distributed, not common, 
Daphnia pulex (Miller). Generally distributed, frequent. 
ie longispina, Miller. Generally distributed, abundant. 
Bosmina longirostris, Miller. In surface tow-nettings, rare. 
Ilyocryptus sordidus (Lievin). South shore, frequent. 
Eurycercus lamellatus (Miller). Generally distributed, not common, 
Acroperus harpa, Baird. North and south shores, frequent. 
Alonopsis elongata, G. O. Sars. South shore, not common. 
Alona quadrangularis, Miller. Common, north and south shores. 
Alonella exigua, Lilljeborg. Frequent, north and south shores. 
a nana, Baird. South shore, scarce. 
Pleuroxus trigonellus, Miller. Common in the loch. 
»  wuneinatus, Baird. In the middle of the loch, scarce. 
Chydorus spheericus, Miller. Generally distributed, common. 
Monospilus tenwirostris, Fischer. South shore, scarce. 
Polyphemus pediculus (Linné). Middle of the loch, scarce. 
Bythotrephes longimanus, Leydig. In the middle of the loch, frequent. 
Leptodora hyalina, Lilljeborg. In the middle of the loch, frequent. 
INSECTA. 
The larve of insects were abundant in the loch, especially the larve of 
the Iphemeridz. The Libellulide and Phryganide were also represented 
in the larval stage more or less frequently. Some idea may be formed of 
the myriads of these organisms present in the loch when it is stated that a 
conspicuous ridge composed of cast-off skins of insect larvee which had 
been washed ashore during the preceding stormy weather extended along 
the margin of the loch for a considerable distance. The curious so-called 
‘water-bears’ (Tardigrada), now included in the class Arachnida, were 
common among the decaying vegetable matter at the bottom. Species of 
Notonectide or ‘ water-bugs,’ and of aquatic Coleoptera were also more 
or less common, though their distribution seemed to be more localised. 
VERMES. 
This division of invertebrates was represented by several species—para- 
sitic and non-parasitic. Among the former were Schistocephalus solidus, 
Crepl., obtained by my son from the body-cavity of a Stickleback (Gas- 
terosteus aculeatus), and a species of tape-worm (Bothriocephalus luatus ?) 
several of which were found in the alimentary canal of the trout, six speci- 
mens being taken from one fish. The heads of the parasites were fixed at 
the extreme end of the ceca or blind tubes of the stomach, and their bodies 
were so elongated as to extend well down into the intestine. Usually 
one parasite occupied a cecum. Tubifex rivulorum was very common in 
the loch. The following species of Annelidz were also obtained :— 
Clepsine 6—oculata. 
Clepsine sp., a very smal] form. 
Nephelis octoculata (2. reticulata, Malm. ). 
