Identifying British freshwater snails: Superfamily: Rissoacea - brackish water species

 

Species associated with brackish-water  habitats

The black and white illustrations of brackish-water species shells in the following pages are reproduced by kind permission of the publisher, Harley Books (B.H. & A. Harley Ltd.), from "Atlas of Land and Freshwater Molluscs of Britain and Ireland" by Dr. Michael Kerney, published in 1999.

The shells illustrated below lack their opercula.

Is the shell a broad cone, its breadth about 70% of its height with a sharply pointed apex and a sealed umbilicus, like this one ?; found in saltmarshes from Kent to the Humber.

If it is NOT like either of these, click here to continue

 

Is the shell broad, about two-thirds of its height, with a blunt apex, the body whorl accounting for 70% of the height, and with a distinct umbilicus ?; found in the upper tidal reaches of rivers between Sussex and Suffolk, and in the south of Ireland.