272 Part III—Ninth Annual Report 
Limnea peregra (Miller). Generally distributed, but not very common. 
5, palustris (Miller). South from the landing-stage, not common. 
»,  truncatula (Miller). North from the landing-stage, not common. 
Physa fontinalis (Linné). North-west end of the loch, rather rare. 
ARTHROPODA. 
CRUSTACEA. 
The Crustacea were by far the most numerous and varied of the inverte- 
brate fauna of the loch. Cladocera and Copepoda occurred in great pro- 
fusion all over and through the water. Daphniz were most abundant. 
Cyclops, especially C. strenwus, were also plentiful; Ostracoda were not so 
common in the loch itself as they were around its margin, particularly 
those parts that were more or less overgrown with vegetation, as round 
the north-east shore. This part of the shore from near the mouth of the 
Powburn to old Leven mouth is very much overgrown with reeds and 
other aquatic plants; in some places the vegetation is so tall and dense 
that it is with some difficulty one can force his way through it. I saw 
here some fine trout hiding among the roots of the tall reeds as I waded 
through among them where they thinned outwards from the shore. 
Seventeen species of Ostracoda were obtained along this part of. the shore; 
twelve species were obtained from the south shore, and only eight from 
the loch itself. Among them were Cytheridea lacustris, a rather uncommon 
species in the eastern counties of Scotland, and one, with the somewhat 
curious name Limnicythere sanctt-patricit, was also moderately common, 
Among the Cladocera the rare and interesting Leptodora hyalina occurred 
in considerable numbers ; Monospilus tenwirostris—the ‘rarest of all the 
Entomostraca ’—was also frequent in the material collected at one or two 
places. The following are the Crustacea obtained :— 
AMPHIPODA. 
Gammarus pulex (Linné). Common all over the loch. 
CoPEPODA. 
Diaptomus gracilis (G. O. Sars). Common throughout the loch. 
Cyclops crassicornis (Miller). Frequent round the margin. 
»,  strenuus (Fischer). Frequent, especially round the margin. 
»,  serrulatus (Fischer). Also frequent with the last. 
Canthocamptus minutus (Miller). Common, especially round the margin. 
Atheyella spinosa (Brady). Frequent in the same localities as the last. 
OsTRACODA. 
Cypria serena (Koch). Common, generally distributed. 
»  ophthalmica (Jurine). Common with the last. 
,, easculpta (S. Fischer). West end, not very commo 
Erpetocypris tumefacta (Brady and Robertson). North and south shores, not 
common. 
om reptans (Baird). Generally distributed, frequent. 
NS strigata (O. F. Miller). Deep water, rare. 
Cypridopsis vidua (Miller). North and south shores, frequent. 
3 villosa (Jurine). Not very common, west end. 
Potamocypris fulva, Brady. North and south shores, frequent. 
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