272 Part III. — Ninth Annual Report 



Limncea peregra (Miiller). Generally distributed, but not very common. 



,, palustris (Miiller). South from the landing-stage, not common. 



,, truncatula (Miiller). North from the landing-stage, not common. 

 Physa fontinalis (Linne). North-west end of the loch, rather rare. 



ARTHROPODA. 



Ceustacea. 



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. Daphniae were most abundant. 

 Cyclops, especially G. strenuus, 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 Cytherldea lacustris, a rather uncommon 

 species in the eastern counties of Scotland, and one, with the somewhat 

 curious name Limnicythere sandi-patrici, was also moderately common. 

 Among the Cladocera the rare and interesting Leptodora hyalina occurred 

 in considerable numbers ; Monospilus tenuirostris — 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 (Linne). Common all over the loch. 



Copepoda. 



Diaptomus gracilis (G. 0. Sars). Common throughout the loch. 

 Cyclops crassicornis (Miiller). Frequent round the margin. 



,, strenuus (Fischer). Frequent, especially round the margin. 



,, serrulatus (Fischer). Also frequent with the last. 

 Canthocamptus minutus (Miiller). Common, especially round the margin. 

 Atheyella spinosa (Brady). Frequent in the same localities as the last. 



Ostracoda. 



Cypria serena (Koch). Common, generally distributed. 

 H ophthalmica (Jurine). Common with the last. 

 ,, exsculpta (S. Fischer). West end, not very commo 

 Erpetocypris tumefacta (Brady and Robertson). North and south shores, not 

 common. 

 ,, reptans (Baird). Generally distributed, frequent. 



,, strigata (0. F. Miiller). Deep water, rare. 



Oypridopsis vidua (Miiller). North and south shores, frequent. 



,, villosa (Jurine). Not very common, west end. 



Potamocypris fulva, Brady. North and south shores, frequent. 



