Another curious femoral variation is the presence of a third trochanter, which Duckworth believes is, to a certain extent, correlated with platymeria. The most convenient frequency table so far compiled is that of Deniker,[1] which shows a range from 13 per cent, for prehistoric Europe to 64 per cent, for the Fuegians of the New World. The great frequency of this trochanter among the Fuegians raises a suspicion as to the remainder of the New World, but satisfactory published data are wanting.
This about exhausts the list of widely diffused common characters for the New World as a whole. As we have seen, the somatic line-up is with the Mongoloid peoples, and, while we are facing this way, attention may well be called to other similarities asserted by certain observers. Posnansky[2] reports the Mongolian spot in the Andean area, and an anatomical peculiarity of the cranium in the maxillar or region of the processus frontalis which is absent in the European, but prominent in Mongolian crania. It seems best, however, to defer further discussion of this subject until we have considered the differentiation of internal New World types and their distributions.
HEAD FORM
Head form has received so much attention that it almost monopolizes the subject matter of physical anthropology. As to what extent this is justifiable, remains to be seen. The special literature for the New World contains a large mass of measurements, both on crania and heads of living subjects, from which we can form some idea of their classificatory value. The most conventional of these measurements is the cephalic index, or the maximum breadth of head divided by the maximum length and the quotient expressed in per cent. Ripley has plotted the distribution of this index on a map of the world,[3] but an inspection of this suggests that the New World cannot be sharply differentiated on the basis of the cephalic index alone. It is true, however, that the broadest heads are here accredited to Asia and the longest have minor represen-
