Range & Status
Primarily western in distribution from Cornwall to Aberdeenshire, with an outlying record for Sussex. There are very few modern records. Foster (1990) provides a national distribution map.
Two records by the author: from the River Kenwyn in 1980 and a small stream at Trebudannon in 1981. Found in the West Looe River by Adrian Brown in 2004.
Habitat & Ecology
Under stones, in moss and on clods of clay in swift flowing, stony streams and rivers.
Pollution of water courses and river improvement schemes.