Volume XXI.

I. Notes on the Social Organization and Customs of the Mandan, Hidatsa, and Crow Indians. By Robert H. Lowie. Pp. 1-99. 1917. Price, $1.00.

II. The Tobacco Society of the Crow Indians. By Robert H. Lowie. Pp. 101-200, and 13 text figures. 1920. Price, $1.25.

III. (In preparation.)