From a number of measurements only is it possible for us to approximate the type of the mound skull. We have already referred to the low type skulls secured by Gen. H. W. Thomas from a mound in Dakota Territory.[233] Unfortunately we are without measurements, but from the description we observe that the forehead is decidedly receding, and the orbital ridges are excessively developed. The inferior maxillary is of unusual prominence and much more massive, as is the entire bony structure, than in the common Indian cranium. Another cranium of similar characteristic was exhumed from the great mound on the River Rouge near its junction with the Detroit River, Michigan, by Mr. Henry Gillman. From this mound several crania were taken, of which one (though evidently adult) presented the hitherto, I think I may say, unprecedented feature of its capacity being only fifty-six cubic inches. The mean given by Morton and Meigs of the Indian cranium is eighty-four cubic inches, the minimum being sixty-nine cubic inches. This cranium, forwarded with other relics to the Peabody Museum, presents (though in no wise deformed) the further peculiarity of having the ridges for the attachment of the temporal muscle only .75 of an inch apart, in this respect resembling the cranium of the chimpanzee. It is rarely that in human crania those ridges approach each other within a distance of two inches, while they vary from that to four inches apart.[234] Eight crania were exhumed by Mr. Gillman from the great mound on Rouge River, which furnished him the following measurements: DIMENSIONS, ETC., OF CRANIA EXHUMED FROM THE GREAT MOUND, RIVER ROUGE, MICHIGAN. KEY: A. _Capacity (Approximate)._[235] B. _Circumference._ C. _Length._ D. _Breadth._ E. _Height._ F. _Breadth of Frontal._ G. _Index of Breadth._ H. _Index of Height._ I. _Index of Foramen Magnum._ J. _Frontal Arch._ K. _Parietal Arch._ L. _Occipital Arch._ M. _Longitudinal Arch._ N. _Length of Frontal._ O. _Length of Parietal._ P. _Length of Occipital._ Q. _Zygomatic Diameter._