52 PRIMITIVE TREPHINING IN PERU (ETH. ANN. 16 
frontal bone extending 32 mm. upward and backward from a point 
34 mm. above the outer margin of the right orbit; and there is an 
irregular contusion in the frontal, 20 mm. to the left of the median line 
and 50 mm. above the right orbit. 
CRANIUM 19 
(Plates XX XIX, XT) 
This specimen is the smallest, most fragile, and most delicately molded 
in the collection; the bone averages 24 or 3 mm. in thickness about the 
Single immense aperture. It was found invested with the sealp, ten- 
dons, and other tissues, but these were mostly removed, leaving only 
occasional shreds clinging to the bones, particularly in the cavities. 
The ligament attachments are better developed than in the average 
Caucasian skull, particularly about the occiput, though less rugose and 
deeply striated than in most of the specimens. The small dimensions 
and several other characters suggest femininity. The age is not easily 
ascertained: The sutures are anchylosed more completely than in any 
other specimen of the collection, yet the dentition is quite immature; 
the anterior molars or “‘seven-year teeth” are barely erupted, and evi- 
dently had not appeared through the gums at the time of death; the 
“wisdom teeth” are rudimentary, being visible through the bone some 
distance (4 or 5 mm. on the right and twice as much on the left) below 
the surface; moreover the mandible is short, allowing absolutely no 
room for the norma! eruption of these teeth. On the whole the cranium 
has an abnormal aspect in several respects. In addition to the lesions 
appearing about the locus of operation, there is a pronounced indenta- 
tion, with some crushing and bruising of the bony surface on the left 
side of the frontal bone 25 mm. from the median line and 40 mm. above 
the orbit (shown in plate XXx1Ix); it partially obliterates one of the 
usual vertical grooves over the temple. A well developed “ Inca bone” 
replaces the superior angle of the occipital. 
The remarkable aperture displayed by this specimen extends from 
near the center of the right parietal forward and downward through 
the frontal to a point 18 mm. above the center of the right orbit; it is 
an elongated oval or ellipse 95 mm. in length and 33 mm. in maximum 
width measured in the plane of the margins, or about 35 by 105 mm. 
measured on the curved surface of the skull. Many marks of instru- 
mentation appear, though the earlier have been obscured or obliterated 
by subsequent scraping or filing. Perhaps the most decisive (which 
unfortunately is not well brought out in the reproduction) is a recti- 
linear incision 23 mm. long defining the antero-superior margin of the 
aperture, of which the terminal portions remain. The anterior termi- 
nal, 6mm. in length, is a groove or cut of the usual V-shape section, 
though more rounded than usual at the bottom, about 1 mm. in width 
and 1.5 mm. in greatest depth, shallowing and narrowing toward the 
