For all Wailaki combined we get a total of 2,760. Cook's figure is 3,350, Kroeber's is 1,000, and Goddard's is between 1,650 and 2,800--average of 2,225. The difference between the figure presented here and Cook's figure is mostly due to the adjustment I have made in the Wailaki boundary from the one used by Goddard. _Mattole._--The village lists of Merriam and Goddard give a total of 42 villages for the Mattole. I have excluded 5 of these from calculation of population estimates, one because it is a summer camp and four others because the frequency appears too great, in places along the coast, to make simultaneous occupation likely. This leaves a total of 37, very likely a conservative estimate since Goddard gives a number of names of villages not located and therefore not included in our calculations. Cook estimates 6 houses per village for the Mattole on the basis of comparison with the Wiyot, Yurok, Tolowa, and Chilula. Goddard counted house pits for a few sites of the Mattole and they appear to average less than that. Not much reliance can be placed on this average, because the sample was very small. However, the number of houses per site is probably not as high as among the Yurok. I have compromised with a figure of 5.4, the same as the estimate for the Sinkyone, the eastern neighbors of the Mattole. Cook takes Kroeber's Yurok figure of 7.5 persons per house in calculating Mattole population. The social organization here is more nearly like that of the southern Athabascans, so I have used 6 per house. This figure gives a total population of 1,200 as against 840 figured by Cook for the Mattole exclusive of Bear River. The difference here is due to the fact that Goddard's village lists were not available to Cook. If they had been, he would have obtained a figure of 1,665, or nearly double his actual estimate. _Lolangkok Sinkyone._--For the Sinkyone on the northern part of the South Fork of the Eel we have a nearly complete village count. South of Larabee Creek Goddard and Merriam give a total of 46 villages. North of Larabee Creek on the main Eel the village count is incomplete, but Merriam gives 8 place names. That these place names represent village names is clear from the Merriam place names farther south which can be checked against Goddard's data. Together, these give a total of 54 villages but leave out the areas of Bull Creek and the upper Mattole River. We may assume 5 villages in each of these, surely a conservative estimate in view of the density of sites on Salmon Creek and South Fork. We thus have an estimate of 64 villages for the Northern Sinkyone. Goddard counted house pits in 24 of the sites he recorded. They come to a total of 162 or 6.7 per village. If we reduce this by 20 per cent to account for unoccupied pits, we get an average of 5.4 houses per site or a total estimate of 346 houses among the Lolangkok Sinkyone. At 6 persons per house this estimate yields a total population of 2,076.