Harold Walter Bell-Marley came to southern Africa from Richmond, Surrey, England, as a British soldier and fought in what is now Zimbabwe in 1896. Subsequently he was on active service during the Anglo-Boer War (1899-1902) and during the Bambatha Rebellion (Natal) in 1906. Back in Britain he left the army and soon returned to Natal, where he worked for a firm of shipping agents at the Point in Durban. He was certainly back in Natal by 1909, for in that year he was issued with a permit to hunt in Zululand. In August 1918 he was appointed as principal fisheries officer in the Natal Provincial Administration, based in Durban, and remained in this position until his retirement in 1937.
Bell-Marley was an ardent naturalist, an enthusiastic collector, and a generous contributor of specimens to museums in southern Africa and overseas. For many years he had a permit to collect in northern Zululand and later spent six weeks each year in the Ubombo area, collecting from there to Lake Sibayi on the coast. Few others collected in this rich but relatively inaccessible and unhealthy part of Zululand. He also collected in many other localities south of the Zambezi, including some in Zimbabwe, Mozambique and Namibia.
Bell-Marley was a founding member of the South African Biological Society (established in 1916). His main interest was insects, and especially beetles, which he studied for more than 40 years, often in association with C.N. Barker*, W.L. Distant*, and others. He published at least one entomological paper, "Some notes on a luminous South African fulgorid insect, Rhinortha guttata Wlk together with a description of its parasitic lepidopterous larvae" (The Zoologist, 1913). However, he supplied the material for many publications by others. His specimens were presented, among others, to the South African Museum, Transvaal Museum, Natal Museum, and Durban Museum.
Another of his interests was in birds and their eggs. As a founding member of the South African Ornithological Society, established in 1930, he represented oology on the society's early council for many years. His extensive collection of birds' eggs went to the Transvaal Museum in Pretoria and he produced papers on the nesting, habits and eggs of South African birds. One of his papers was "An account of eggs collected on the Pongola River, North Zululand" (The Ostrich, 1933). In recognition of these contributions he was elected and honorary life member of the society in 1942.
Bell-Marley collected molluscs from the stomachs of deep sea fish and sent them to the United States for further study. The land snails and slugs that he collected in Zululand were sent to H.C. Burnup*. His collection of shells was distributed to several museums and was consequently never studied as a unit. He also collected mammals, crabs, fish and plants. An extensive series of sketches of Natal marine fishes by him, based on freshly killed specimens, went to the Natal Museum. Some of these sketches were published by E.C. Chubb* and J.L.B. Smith. The longnose pygmy shark, Heteroscymnoides marleyi was named for him by the American zoologist Henry W. Fowler in 1934.
During his last visit to northern Zululand Bell-Marley contracted blackwater fever, a most dangerous complication of malaria, and died soon after his return to Durban.