A more serious possible source of error concerns the question of which and how many sites were simultaneously occupied. When there is a complete village count, I have excluded from consideration known summer villages, villages not on main salmon streams, and other villages of doubtful status. Even so, the villages run about one per mile along the salmon streams and the possibility presents itself of movement from site to site, perhaps in response to varying fishing conditions. If this was the practice, then the population estimates might have to be reduced by half or even more. But there is no concrete evidence to support such a theory and it is a fact that the Goddard material gives quite complete information of this kind. Therefore, if the present calculation is an overestimate, it is not a very great one. ESTIMATES BASED ON VILLAGE COUNTS _Wailaki (Eel and North Fork)._--The present list gives a total of 67 villages among the Eel River and North Fork Wailaki. For purposes of calculating population I have excluded 13 of them (nos. 6, 9, 16, 31, 38, 40, 51, 57, 58, 59, 61, 66, 67) because they are summer camps in the hills, rock shelters used only briefly, or specialized fish-drying camps. These places do not seem to have been used simultaneously with the main villages. This list appears to be a substantially complete count from Horseshoe Bend south, but it is clear that neither Merriam nor Goddard visited the area north of this, and the village count suffers as a result. There are about 16 river-miles south of Horseshoe Bend, including both the main Eel and North Fork, and there are 49 main villages on this stretch, yielding an average of 3.1 per river-mile. If we apply this figure to the 7 river-miles above Horseshoe Bend, we get 21.7 villages for that stretch rather than 5, as given by ethnographers. We may reduce this figure to 15, because this stretch of the river appears to offer a less desirable location (Goddard, 1923_a_, p. 107). This calculation gives a total of 69 villages for the entire group, considerably less than Cook's total of 87 (Cook, 1956, p. 104). The reason for the difference is that Cook bases his estimate on Goddard's data, with the territory of the Wailaki extending above Kekawaka Creek, whereas I have taken Kekawaka Creek as the boundary.