John Gwyn Jeffreys (1809–85)

Conchologist, zoologist, and lawyer. Solicitor in Swansea until 1856, when he was called to the bar and moved to London. JP for Glamorgan, for Brecon, and for Hertfordshire. Deputy lieutenant, Hertfordshire; high sheriff, 1877. Treasurer of the Linnean Society of London and the Geological Society of London for many years. Conducted extensive deep-sea dredging researches. FRS 1840.