The Siouan family includes the Dakota, Assiniboin, Omaha, Ponka, Osage, Kansa, Kwapa, Iowa, Oto, Missouri, Winnebago, Mandan, Hidatsa, Crow, Tutelo, Biloxi, Catawba, and other Indians. The Sapona, who are now extinct, probably belonged to this family. The author was missionary to the Ponka Indians, in what is now part of Nebraska, from 1871 to 1873. Since 1878 he has acquired native texts and other information from the Omaha, Ponka, Osage, Kansa, Winnebago, Iowa, Oto, Missouri, and Dakota. In seeking information respecting the ancient beliefs of the Indians the author has always found it expedient to question the Indian when no interpreter was present. AUTHORITIES. § 2. This study is based for the most part upon statements made by Indians, though several publications were consulted during the preparation of the fifth and sixth chapters. The following Indians had become Christians before the author met them: Joseph La Flèche, Frank La Flèche, John Big Elk, and George Miller, all Omaha. Joseph La Flèche, who died in 1888, was the leader of the civilization party in the Omaha tribe after 1855. He was at one time a head chief. He spoke several Indian languages, having spent years among other tribes, including the Pawnee, when he was in the service of the fur company. His son, Frank, has been in the Indian Bureau at Washington since 1881. The author has obtained considerable linguistic material from the father and son. The father, with Two Crows, aided the author in the summer of 1882 in revising his sociologic notes, resulting in the preparation of “Omaha Sociology,” which was published in the third annual report of the director of the Bureau of Ethnology. John Big Elk, a full Omaha, of the Elk gens, furnished an article on “Sacred Traditions and Customs,” and several historical papers, published in “Contributions to North American Ethnology, Vol. VI.” George Miller, of the Ictasanda or Thunder gens, is a full Omaha, from whom was obtained nearly half of Chapter III, including most of the Omaha illustrations. The following Indians were not Christians: Gahige, Two Crows, Ԁaȼiⁿ-naⁿpajĭ, and Samuel Fremont, all Omaha; Nudaⁿ-axa, a Ponka; and the Kansa, Osage, Missouri, Iowa, and Winnebago informants. Two Crows has been connected in several ways with the ancient organizations of his people. He has been a head man, or nikagahi, being thus an ex-officio member of the class which exercised the civil and religious functions of the state. He has been a policeman during the buffalo hunt. He has acted as captain, or war chief, and he is the leading doctor in the order of Buffalo shamans, being the keeper of the “sweet medicine.”