Notes on British Hydrobia with description of a supposed new species

found it in myriads between Greenwich and Charlton, but at the present time neither Mr. Jeffreys nor myself can find it there.We have, however, found it in countless thousands at Abbey Wood and Erith, on the raised banks of the Thames, which now seems its nearest locality to London, so that they appear to have migrated for a distance of about ten miles."As Mr. Horsley has been searching for this species also at the supposed new species."