Of Gifford's 67 names, 2 may be deducted as being only camps, leaving 65 which at some period were permanently occupied. In his Appendix A (pp. 57-61) he lists the sites, together with the number of houses in each and the number of males and females inhabiting them. From these data may be computed the total number of families and the mean number of persons per family. There were 227 families in all. However, 36 of these are listed two or more times by virtue of moves made from one hamlet to another, which were remembered by Gifford's informants. This would leave 191 families for the subtribe, provided Gifford recorded all the moves. But Gifford clearly implies that he did not, since his informants could not remember them all. Hence the number of families must be further corrected. In Appendix A, 15 out of a total of 65 hamlets were concerned in the moves recorded. These 15 hamlets were inhabited at different times by 61 families but many of these, owing to frequent change of residence, are repetitions. Actually there was a total of 24 _different_ families rotating among the 15 villages. Now if in the other 50 hamlets the same process was going on, although Gifford was not able to record the moves, it is legitimate to apply the same ratio as is in fact found for the 15 hamlets. The crude total of 227 families must therefore be reduced to 89. From Gifford's complete list it can be determined that there were on the average 4.93 persons per family. This gives a population of 439 for the period remembered by the informants. On general grounds it is to be expected that the conditions reported by Gifford's informants were not entirely aboriginal. This is also indicated by the value of 4.93 persons per family, which is somewhat too low for a stable prehistoric population. Moreover, Gifford himself states that there were formerly 44 more houses than there were in the time referred to by the informants (figures given individually for the hamlets in App. A). About 1850 there were 227 houses, and if 44 are added, the aboriginal number would have been 271. Each house may be assumed to have held one family but the houses were probably occupied in rotation. The crude estimate of 271 houses or families, each containing (according to aboriginal standards) a possible 6 persons, would mean a total of 1,626 for the subtribe. If, however, we apply the correction factor for family moves we must reduce this estimate to 640, a far more reasonable figure. For the North Fork Mono, therefore, we may accept as the best estimate obtainable a population of 440 for the period near 1850 and of 640 for precontact time. The other subtribes of the Mono provide no data comparable with those available for the North Fork group. Some method of extrapolation is thus called for.