380 BUREAU OF AMERICAN ETHNOLOGY [BULL. 33 
He remarks in closing that— 
The only apparent doubt about the great antiquity of this skull is its perfect 
preservation, but this is owing to the material in which it was found. There are 
other instances in this same locality of like preservation not petrified. 
The foregoing excerpts constitute the total of extant records con- 
cerning the find. It is plain that Mr. McConnell was an amateur 
collector and geologist and that the Rock Bluff skull attracted his 
attention mainly by its unusual shape. His notes concerning the 
geology of the find are so meager that no important conclusion can be 
based on them. That Schmidt, and after him Kollmann, were in- 
clined to class the skull as geologically ancient could have been due 
only to.an imperfect acquaintance with these records and to the low 
forehead of the cranium. At the time of Schmidt’s and Kollmann’s 
writings sufficient osteological material from the valley of the Ilh- 
nois river did not exist to enable them to determine the range of 
cranial variation in that region. 
The skull itself (plate 1, @) is now part of the National Museum 
collections. Though somewhat injured, especially about the face, it is 
remarkably well preserved, in no way deformed or affected by disease, 
and not at all fossilized. It is dirty yellowish-white in color and 
shows on the left side superficial injuries, which appear as if due 
partially to cutting with an edged implement and partially to the 
gnawing of rodents, but these are of little significance. Morpho- 
logically, the skull is quite remarkable. Its most noteworthy fea- 
ture, and that which gives it the appearance of a specimen of a low 
type, is its greatly developed supraorbital ridges. These are not in 
the form of arcs, however, as in anthropoids and in the human skulls 
of Spy, Neanderthal, and, to a less extent, in the two Calaveras speci- 
mens, but involve, as general among Indians, only about the median 
three-fifths of the supranasal and supraorbital portions of the frontal 
bone. They project greatly forward, however. The extent of pro- 
jection amounts to 1.1 em. on the right and 1 cm. on the left side in 
front of a plane passing through points situated on the dorsal side of 
the middle of the supraorbital borders, or 2.5 cm. on the right and 2.4 
em. on the left side, in front of a vertical plane touching on each 
side the anterior extremity of the malo-frontal suture. This great 
prominence of the ridges brings forward the whole supranasal region, 
making the forehead, naturally quite low, appear still lower and 
unusually sloping. It is this extraordinary development of the 
median part of the supraorbital ridges more than deficient develop- 
ment of the frontal part of the cranial cavity that gives this skull 
its aspect of inferiority. There is still another feature which points 
to mediocre development of the cranium, and that is the position 
of the petrous wedges* in relation to the neighboring parts of the 
¢ Both unusually broad in this specimen, 
Oe ee eR 
