ANATOMICAL MEASUREMENTS. 249
The great and uniform differences between these heads and those. of the American Indians, will be obvious to every one accustomed to make comparisons of this kind, and serve as corroborative evidence of the opinion that the Eskimaux are the "only people possessing Asiatic characteristics on the American continent.
These measurements are derived from one hundred and forty-seven skulls of American Indians of forty different nations and tribes; and the crania are all of adult persons, and unaltered by art. The table is itself sufficiently explanatory for general purposes, but it is necessary to premise- the manner in which the measurements have been taken.
The longitudinal diameter is measured from the most prominent part of the os frontis, between the superciliary ridges, to the extreme end of the occiput.
The parietal diameter is measured between the most distant points of the parietal bones, which are, for the most part, the protuberances of these bones.
The frontal diameter is taken between the anterior inferior angles of the parietal bones.
The vertical diameter is measured from the fossa between the condyles of the occipital bone, to the top of the skull.
The inter-mastoid arch is measured, with a graduated tape, from the point of one mastoid process to the other, over the external table of the skull.
The inter-mastoid line is the distance, in a straight line, between the points of the mastoid processes.
The occipito frontal arch is measured by a tape over the surface of the cranium, from the posterior margin of the foramen magnum to the suture which connects the os frontis with the bones of the nose.
The horizontal periphery is measured by passing a tape around the cranium so as to touch the os frontis immediately above the superciliary ridges, and the most prominent part of the occipital bone.
The length of the head and face is measured from the margin of the upper jaw, to the most distant point of the occiput.