Probably under recorded but only known from a relatively small number of sites.
Found in strongly brackish water (10-33ppt) in sheltered lagoons and marsh drains. Lives permanently submerged with species such as Enteromorpha, Zostera and Potamogeton.
3-4mm
Lives in low to moderate salinities (5-25ppt) in quiet estuaries, ponds behind shingle bars, and lagoons and drainage ditches in coastal marshes. Generally sheltered places without direct connection to the sea. Tends to live permanently submerged on mud or vegetation (especially Enteromorpha and Potamogeton).
4-6mm
Found in damp places such as damp woods, marshes, lake margins, flushes and dune slacks. Generally intolerant of human disturbance.
Shell short (1.7-1.9mm) and barrel-shaped with the penultimate whorl often slightly wider than the body whorl. Mouth edge thin, not strongly reflected: a slight transverse thickening just behind the lip. Aperture with 5 - 6 teeth; 2 parietal, 1 - 2 columellar, 2 palatal. Shell pale brown with very fine regular striations.
Frequently found in the roots of grass in dry calcareous places such as roadside banks, chalk/limestone hillsides, cliffs and screes and the hollows of stabilised dunes. Intolerant of shade and not usually found in woods.
Aperture with 4 - 7 prominent teeth (1 parietal only),usually linked by callus around the bases :externally there is a strong pale transverse crest a little before the aperture. Mouth edge slightly thickened, not strongly reflected. Shell pale brown with a characterisic sculpture of very fine, regular ribbing.
Widespread but local.Widespread but local, reaching the Artic circle in Scandinavia.
Rather dry places. Most typically on or at the base of ivy-covered stone walls, usually shaded by trees but also recorded from rocks, ground litter in open woodland, hedge banks, natural cliffs and occasionally in fixed sand dunes.
Typically 2.0 x 1.1 mm. 6 - 9 very prominent apertural teeth almost filling the aperture; sculpture smooth with irregular growth lines.
Calcareous fens and marshes; often at the edges of lowland rivers and lakes. Normally lives close to the ground on sedges and grasses but may also be found on taller marsh vegetation such as Phragmites and Alnus. Not tolerant of human disturbance.
Generally 2.2-2.7 mm in height. Shell broadly oval; the body whorl accounts for nearly two-thirds of the total height; aperture relatively large and triangular with an indented outer margin; 4 - 5 well-defined apertural teeth, 1 parietal, 1 columella, and 2 palatal, the palatals linked by a callus.Shell yellowish- or reddish-brown, glossy and tranlucent.
Endangered
North facing corries between 800m and 980m amongst short turf and low heath / scrub rich in Artic alpines.
Shell more cylindrical; aperture relatively smaller and rounded. 3 - 4 very small deeply-set apertural teeth, 1 parietal, 1 columellar, 1 lower palatal (sometimes absent, and sometimes an additional upper palatal). Mouth edge simple and scarcely thickened. Shell pale yellowish-brown, translucent, not glossy, but with a silky sheen due to many reguler fine growth lines.
Rare
Saturated decaying vegetation in marshes and alder fens at the margins of lakes and rivers usually in places subject to flooding. Tolerates acidic conditions.
Typically 1.9-2.2mm in height. Shell relatively broad, almost ovoid; with 5 strongly tumid whorls, the last well-rounded and relatively large; mouth-edge delicate, with a transverse furrow just before the aperture.
Endangered
Upland neutral to calcareous marshes or flushes with a stable water level. Requires low growing luxuriant vegetation doiminated by finer leaved grasses and sedges.
Whorls strongly tumid; mouth edge thinner and convex with no transverse rib behind the outer lip; apertural teeth simple and peg-like, arising without surrounding callus; colour pale reddish-brown; shell glossy, with fine regular growth-lines.
Endangered
Marshy ground: characteristic of calcareous flushes on north facing mountain hillsides.
Typically 1.7mm to 2.1mm in height. Shell rather barrel-shaped; mouth edge scarcely thickened, outer lip just perceptively reflected. No external rib or flexure behind lip. Mouth rather rounded, without teeth, or occasionally with a vestigial parietal denticle only. Shell pale reddish-brown, very smooth and glossy.