Born at Roscrea, Co. Tipperary and educated at Queen's College, Galway and the Royal School of Mines, South Kensington. Entered the NHM as an Assistant in the Zoological Department in 1886 and eventually became Keeper of the recently formed Entomology Department in 1913. Gahan was an entomologist of wide interests but studied the Coleoptera in particular, especially the families belonging to the Phytophaga, the Elateridae and the Cerambycidae. The latter formed his most important publication which was the volume on this group in the FBI. More than 100 other notes and articles dealt primarily with descriptions of new foreign species. Gahan retired from the NHM in 1927 when he moved to Mount Aylsham in Norfolk where he died. The History of the Collections Contained in the Natural History Departments of the British Museum, 2, 1906, pp.554-55, records that Gahan's work shortly after his appointment to the Museum involved a complete revision of the Cerambycid collections. This subsequently included the addition of the Godman/Salvin collections of longhorns, the incorporation of which he completed in 1902. His work on the Phytophaga commenced in 1890 and again included the incorporation of the Godman/Salvin collections, particularly the Cebrionidae, Rhipiceridae, Dascillidae, Lycidae and Lampyridae. Work on the Elateridae was prompted by the arrival of the Janson collection presented by Godman in 1903 which was re-arranged by Gahan from 1904. Pedersen (2002) pp.80,126 lists correspondence in the RESL. FRES from 1887. President 1917-1918; Vice President, 1916 and 1919, Secretary 1899-1900; and Council 1893-1895, 1901, 1914-1916, 1919. He was also a member of the SLENHS. Gilbert (1977) lists eight obituaries and other notices. (MD 1/03, 11/09)
Dates
20 January 1862 - 21 January 1939