About 1cm in diameter - whorls gradually enlarge
No interactions present.
This is a terrestrial snail of some sort. Hydrobiidae are small with a tall spire i.e. Potamopyrgus.
I guess it could be as the shell was empty although I did base the observation using a key to freshwater snails (Freshwater invertebrates by P.S Croft) and it fits in nicely with key and picture. Book says Order Prosobranchia, family Hydrobiidae, family Valvatidae Valvata valve snail. Is it saying it could be Hydrobiidae or Valvatidae, I'm confused now! I have found another picture that fits well - http://en.wikipedia.org/wiki/Valvatidae
Lat/Lng: 51.4221, -2.6104
OS grid ref: ST576694
Fast flowing shallow river at the bottom of a wooded valley.