its natives, and their languages before emigrating to the U.S. in 1852. Africa He was sent in 1855 by the Academy of Natural Sciences at Philadelphia on an African expedition. Until 1859, he explored the regions of West Africa in the neighborhood of the equator, gaining considerable knowledge of the delta of the Ogooué River and the estuary of the Gabon. During his travels from 1856 to 1859, he observed numerous gorillas, known to non-locals in prior centuries only from an unreliable and ambiguous report credited to Hanno the Navigator of Carthage in the 5th century BC and known to scientists in the preceding years only by a few skeletons. He brought back dead specimens and presented himself as the first white European person to have seen them. A subsequent expedition, from 1863 to 1865, enabled him to confirm the accounts given by the ancients of a pygmy people inhabiting the African forests. Du Chaillu sold his hunted gorillas to the Natural History Museum in London and his "cannibal skulls" to other European collections; a fine cased group shot by Du Chaillu may be seen in the Ipswich Museum in Suffolk, England. Narratives of both expeditions were published, in 1861 and 1867 respectively, under the titles Explorations and Adventures in Equatorial Africa, with Accounts of the Manners and Customs of the People, and of the Chace of the Gorilla, Crocodile, and other Animals; and A Journey to Ashango-land, and further penetration into Equatorial Africa. While in Ashango Land in 1865, he was elected King of the Apingi tribe. A later narrative, The Country of the Dwarfs was published in 1872. At the time, he was in great demand on the public lecture circuits of New York, London, and Paris. Although there were initial challenges of his accounts, they came to be accepted, although Encyclopædia Britannica speculated that "possibly some of the adventures he described as happening to himself were reproductions of the hunting stories of natives." In addition to his zoological work on gorillas, Du Chaillu collected and identified a number of new species to science. He was the first person to scientifically describe the giant otter shrew (Potamogale velox), taking precedence over John Edward Gray's description of the same animal as a mouse instead. He also collected the type specimens for the southern needle-clawed bushbaby (Euoticus elegantulus), the hammer-headed bat (Hypsignathus monstrosus), and the African pygmy squirrel (Myosciurus pumilio),