During a recent examination of some Coal Measure non-marine lamellibranchs in the collections of the British Museum (Natural History), my attention was drawn to a specimen from the Sowerby Collection labelled “Unio subconstrictus J. Sow., Coal Measures, Derbyshire”. On the back of the specimen were the remains of an original label, partly defaced, which some previous worker had endeavoured to read, for the words “Chapel … Sheffiel[d]” had been neatly copied on to another label affixed to the specimen.