Alinda biplicata,[3][4] also known as Balea biplicata, common name the two lipped door snail or Thames door snail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium.
This species is known to occur in a number of European countries and islands including:
This species is rare in Great Britain. In England, it is found mainly in the London area, almost exclusively along the River Thames, and is particularly preserved at Isleworth Ait.[5] There is also a colony at Purfleet in Essex.[6]
Like all species in this family, this snail has a clausilium. This spoon-shaped "door" is supported by, and slides in, a series of internal shell folds, see the image below.
The weight of the adult live snail is 148.6±5.7 mg.[7]
Alinda biplicata, also known as Balea biplicata, common name the two lipped door snail or Thames door snail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium.