HRDLICKA] SKELETAL REMAINS oL 
base. When the base of the skull is viewed from above, it is seen 
that the inferior surface of the right petrous portion is but slightly 
depressed, while that of the left is on the level, and anteriorly even 
slightly above the level, of the neighboring parts—always a sign of 
rather deficient expansion of the cranial cavity, for in a well-expanded 
specimen the petrous portions are seen in a decided hollow. The 
skull shows large mastoids and a well-developed superior occipital 
erest, indicating a powerful musculature; but the temporal ridges 
are not pronounced and their nearest approach to the sagittal suture 
amounts on each side to nearly 6 em. The face was apparently but 
moderately prognathic, as is general in Indians, and the malars and 
the zygome were not above medium in strength. The nasal spine 
is low and not very prominent, but this feature constitutes no great 
exception among Indian crania. The palate, the dental arches, and 
the teeth were of only ordinary dimensions; the injured condition 
of the arches and absence of the teeth prevent the giving of meas- 
urements. The foramen magnum is large, indicating probably tall 
stature. The glenoid cavities are deep and spacious. The lower 
jaw, which was originally with the specimen, is wanting, but accord- 
ing to Meigs’s illustration and Schmidt’s account, it showed nothing 
that would be uncommon in the lower jaw of a modern Indian. 
The National Museum collection contains a good series of Indian 
crania obtained from mounds along the Illinois river, with which the 
Rock Bluff skull can be compared; and there are several skulls 
from the Albany mounds, Illinois, in the Davenport Academy of 
Sciences, which can also be utilized in this connection. These mound 
crania are certainly not geologically ancient, though they probably 
antedate the advent of whites into the valley. They show some variety, 
due possibly to tribal mixture, but the predominating type 1s dolicho- 
cephalic, having rather low orbits and, in males, strongly developed 
supraorbital ridges, with narrow, low, and occasionally very sloping, 
forehead. Mesocephalic forms appear occasionally. With most of 
these skulls the Rock Bluff specimen agrees fairly in every essential 
particular that goes to form a cranial type. Its supraorbital ridges 
alone are quite equaled by those of no. 4401, Davenport Academy 
(plate xim, a), and in several other specimens they are closely ap- 
proached. Were the Rock Bluff skull mingled with the rest of the 
Illinois River. male crania no observer would be likely to single it out 
as especially remarkable. It agrees with most of them even in color. 
The peculiarities it presents are well within the scope of individual 
variation. The following table and illustrations (plate m, b, ¢) show 
the resemblances, which are still further strengthened by an exami- 
nation of the whole series of specimens from the Illinois valley. 
In view of the above facts, and irrespective of the wholly unsatis- 
factory geological evidence, the Rock Bluff skull, though regarded 
