Letters from Carl Jacob Sundevall, Director of the Royal Museum Stockholm, to Philip Lutley Sclater regarding specimens found in the Museum such as Galapagos birds

Letters from Lionel Walter Rothschild, 2nd Baron Rothschild, to Philip Lutley Sclater regarding an expedition to the Sandwich Islands, papers on birds of the Sandwich Islands, drawings of a Rail, ornithological exhibitions, the sale of a rhinoceros, his drawing of a rhinoceros to be published in the Proceedings of the Zoological Society of London, his Cassowaries at Tring, a transfer of Tragelaphus, Galapagos Tortoises, Eclectus Parrots, Lemurs and Zebras

Correspondence with the New York Zoological Society regarding the diet of Humming Birds from Ecuador

Letters from William Henry Hudson to Philip Lutley Sclater regarding cuckoos, shipments of birds to the Smithsonian, Woodpeckers in Argentina, Blackbirds and other birds

Letter regarding a decree of the Ministry of Economy and Commerce in Chile regarding the capture, buying, selling and transport of birds

Correspondence with Gerald Durrell regarding animals to be deposited at London Zoo, the exchange of Gough Island Moorhens for a pair of Rheas, a publication by the International Union for the Preservation of Nature on extinct and vanishing birds, a trip to Argentina, the diet of Giant Pangolins, and the care of Notornis