John Henry Ponsonby, an English conchologist who specialized in the study of land and freshwater species, was the eldest son of Sir Spencer Ponsonby-Fane, an English cricketer and civil servant. John Henry worked as a clerk in the Privy Council Office but in 1875 became a partner in the banking firm of Herrie, Farquhar and Company. From there he later transferred to Lloyds Bank. Also in 1875 he married Florence Farquhar, with whom he had a son and a daughter. Later he extended his surname to Ponsonby-Fane. He suffered from ill health for much of his life.
Ponsonby had a keen interest in molluscs from an early age. He assembled a large general collection, but later specialized mainly in helicoid land shells, terrestrial operculates and some other groups. He published some early papers on the land shells of Gibraltar (1883, 1888), the land and freshwater shells of the Maltese Islands (1885), two new species of land shell from Tenerife (1895), and a new species from the island Buru, in Indonesia (1899). He visited South Africa at some time, probably around 1890. From that year to 1899 James C. Melville and he published eight papers, one of them in 11 parts, on the non-marine Mollusca of South Africa in the Annals and Magazine of Natural History and the Proceedings of the Malacological Society of London. In these papers, which constituted a major contribution to the subject, they described many new species and provided a check list. Several South African species were named after Ponsonby, both marine (Euthria ponsonbyi, Lyria ponsonbyi, Petricola ponsonbyi, Tellina ponsonbyi, Turbo ponsonbyi) and non-marine (Gulella ponsonbyi, Fauxulus ponsonbyanus).
