208 The Scottish Naturalist. 



L. auricularis L. In ponds, &c. Very rare and local. Pond 

 in Abercorn Park" (Forbes and Hanley, iv. 171); " Monkland 

 Camfl" (Dougall, Trans. Glasgow Nat. His. Soc, I. 192). 



L. stagnalis L. Ponds and marshes. Very rare and local. 

 Possil Marsh, Glasgow. 



L. palustris Mull. — Common in muddy ponds and streams 

 from Aberdeenshire south. Several varieties occur. 



L. truncatula Mull. — A common and widely distributed spe- 

 cies, inhabits muddy ponds and slow running streams, and often 

 found adhering to plants and stones out of the water. 



L. glabra Miill.— Rare and local. Frankfield Loch, near 

 Glasgow (Dougall, Trans. Glasgow Nat. His. Soc. I. 193). I 

 have rfound it in shallow pools on the Muir of Durdie, near 

 Perth. Almost every specimen in this locality has the three 

 apical segments eroded. ( = var. decollata, B. W., Trans. Perth- 

 shire Soc. Nat. Sc. I.) 



Ancyhts fluviatilis Miill. — Common and widely distributed, 

 inhabits streams, adhering to stones in the currents. I have 

 found it at an elevation of 2200 feet. 



A. lacustris L. — Much more local than the last, found as far 

 north as Aberdeenshire, living in ponds and adhering to the 

 stems and leaves of plants, as the water-lily, Iris, &c. I have 

 found it, in Duddingston Loch, on the leaves of Stratiotes, a 

 habit which Linne notices. All the Perthshire specimens ap- 

 pear to belong to the var. albida. 



Acme lincata Drap. — Rare and local. In damp places under 

 stones, or in moss and dead leaves. From " Lanarkshire to 

 Cornwall" (Jeffrey's B.C. I. 308), " Inverary and Isle of Skye " 

 (Forbes and Hanley, IV. 290). 



Bythinia tentaculata L. — Local. In canals and slow streams. 

 Frazerburgh, Aberdeenshire, and near Glasgow. I have not 

 met with this in Scotland. 



Paludina vivipara L. — "Findhorn, Moray Frith" (Rev. Dr. 

 Gordon). , 



Valvata piscinalis Miill. — Widely distributed and, though 

 local, not uncommon. In ponds, lakes, and gentle streams. 



V. cristata Miill. — In similar situations, but either over- 

 looked or much rarer than the last, though widely distributed. 

 I have not found it. It is often attached to roots of water- 

 plants. 



Neritina Jlin'iatilis L. — On stones or among gravel in streams. 

 " From the Orkneys to Cornwall." — Jeffreys. 



