30 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 iftaterial 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 Illi 

 nois river did not exist to enable them to determine the range of 

 cranial variation in that region. 



The skull itself (plate n, a) 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 cm. 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 

 cm. 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 



a Both unusually broad in this specimen. 



