The areas with which we are dealing are reasonably large; they are also relatively homogeneous in the ecological sense. All lie within the redwood-transition belt (except the Wailaki, which border it on the east), and all are characterized by small, perennial, salmon-bearing streams, along which the Indian villages were placed. There is nothing outstandingly different about the terrain occupied by the Lassik, Nongatl, and Sinkyone, except that perhaps it lies somewhat higher on the streams (but the Wailaki are still higher) and contains fewer flats and open valleys. The three tribes being considered had respectively 325 square miles, 700 square miles, and 615 square miles of territory. If the density was 4.96 persons per square mile the population would have been, to correspond, 1,612; 3,472; and 3,050. If we allow for a somewhat poorer habitat, these values may be reduced a little, say to 1,500; 3,300; and 2,900. It is difficult to see how the estimates can be carried much lower. _Nongatl, Lassik, and Sinkyone ... 7,700_ THE WAILAKI The Wailaki were studied by Goddard (1923, 1924), who published two papers concerning them. The first covered the main portion of the tribe along the Eel River and the second the Pitch group which lived along some of the tributaries of that river. Goddard found the Wailaki proper, as they may be termed, to consist of 18 communities or subtribes, each living in one to several villages, and the Pitch group to consist of 4 subtribes. One peculiarity of the villages was that they were inhabited only during the six winter months, the people in the summer dispersing through the hills in search of small game and plant food. Although the villages were occupied only half the year, nevertheless they can be used for computation of population since there were no other fixed abodes with which they can be confused. In addition to Goddard's monographs, we have a tribe list for a portion of the Wailaki from Merriam entitled "Tsennahkennes Bands and Rancherias." Both investigators surveyed independently 11 of the 18 subtribal areas and obtained the names of villages from informants. In his list on page 109 and in his text Goddard identifies 53 inhabited places. For two other subtribes, the Chiskokaiya and the Kaikichekaiya, he cites the villages by name in the textual descriptions on pages 106 and 107. There are a total of 18 for the two subtribes. Villages were not determined at all for the five northern subtribes.