The provenance of the only known egg of the extinct Tristan Moorhen Gallinula nesiotis

Tristan Moorhen Gallinula nesiotis is a rail from Tristan da Cunha in the South Atlantic Ocean that probably went extinct around 1874. Here, we describe the only known egg of the species, its history, and confusion surrounding its attribution. It was probably collected by (or given to) Revd. W. F. Taylor sometime between 1851 and 1856, shipped aboard HMS Frolic in 1856, and presented as a gift to Lady Eliza Lucy Grey, wife of Cape Colony Governor Sir George Grey.