15 



Hereabouts it is rare; the only locality I have dis- 

 covered is a drain near the Beeston Railway Station. 



It is found in Cambridgeshire and Surrey (Jenyns), 

 near London (Grey), Kent and Dorset (Montagu), Bal- 

 macarra, West Ross (Jeffreys), Arthur's Seat, Edin- 

 burgh (Brown), and the Wells of Weary (Brown). . 



On the Continent it occurs in Sweden (Nilson), and 

 in Germany (Pfeiffer). 



PisiDiuM PULOHELLUM (The Beautiful Pera). Jenynt 

 The Beautiful Pera is very various in shape. It has 

 regular eoncentric strioe. The usual length is 1^ lines 

 by 1:1 lines. 



In this neighbourhood it is rare, being, a" yet, only 

 found in the Musco-sic dyke, and another near Beeston, 

 Other habitats are, Cambridgeshire and Surrey 

 (Jenyns), Northumberland and Durham (Alder), Scar- 

 borough (Bean), Preston (Sovs^erby), Birkham Common, 

 in Surrey (Grey), Norfolk (Bloxam), Kent and Dorset 

 (Montagu), Cadiey, near Swansea (Jeffreys), generally 

 distributed in Ireland (Thompson). Edinburgh (Brown), 

 and Aberdeenshire (Macgillivray). 



PisiDiuM pusiLLUM, (The Minute Pera). Turton. 



The form of this shell is a rounded-oval, with broad 

 umbones. Like Cyclas cornea, it is subject to consider- 

 able diversity in its form. The shell is thin and semi- 

 transparent, although the epidermis is usually of a dull 

 colour. The length is If lines, and the breadth nearly 

 1 J lines. 



It is an inhabitant of ponds, slow rivers, drains, and 

 marshy places. 



Amongst the localities in Nottinghamshire may be 



