56 Our British Snails 



Liynncea {Amphipeplea) glutinosa. — Very local. 

 Somewhat like Ph. fontinalis, bat larger and more 

 thin. In young specimens the mantle covers 

 the shell, and in adults the animal is not wholly 

 contained in the shell. 



Limncea {suh-genus Radix) involuta. —Only 

 found in one Irish tarn. Whorls envelop the 

 spire. Very thin, pale amber. 



Limncea [Radix) peregra. — The most common 

 and variable of all our freshwater shells. Spire 

 pointed. Somewhat amphibious. Found practi- 

 cally over the whole of the Eastern Hemisphere. 



Limncea {Radix) auricularia.- — Mouth very large, 

 with outer lip widely reflected. Very common 

 and fine in the Thames. Spire very short, 

 apex sharp. 



Limncea {suh-genus Limnophysa) stagnalis. — 

 The largest of the genus. Common, except in 

 Wales. Shell greyish, spire long and tapering 

 to a point ; 12210 teeth on its lingual ribbon. 

 See the illustration on p. 57, which also shows 

 above two specimens of Paludina contecta, one 

 being covered (as freshwater shells often are) by 

 a vegetable growth, which obscures the markirg. 



Limncea {Limnophysa) palustris. — Shell tapering, 

 somewhat solid, brown, much smaller than stag- 

 nalis. Common in slow or stagnant water. 

 Some varieties much darker than the t3^pe. 



Limncea {Limnophysa) truncatula. — Like the 

 last in shape, but much smaller, and with a deeper 



