30 PRIMITIVE TREPHINING IN PERU [BTH. ANN. 16 
The operation, located in the frontal bone on and to the left of the 
median line, cornering just above the left orbital ridge, was incomplete. 
It comprised two approximately orthogonal trios of approximately 
rectilinear incisions, each similar to those of the preceding specimens, 
so placed as to describe four contiguous quadrilateral buttons, of which 
one remains in place. The aperture, if completely opened, would aver- 
age about 30 by 37 mm. The six incisions are V-shape in section, nar- 
rowing and shallowing to the termini, and project 5 to 14 mm. beyond 
their orthogonals; and there are a few random scratches, giving the 
usual testimony concerning the character of the instrument employed. 
The incompleteness of the opening, in conjunction with the relations of 
the incisions, indicate clearly the procedure of the operator. Evidently 
the operation was begun with only a vague notion as te the dimensions 
of the button to be removed, and the operator clumsily located the 
incisions in indefinite fashion rather than in accordance with a clearly 
formed plan; and as the two outer incisions approached the supra- 
orbital ridge they were diverted by that prominence in such manner as 
to give them, particularly the longitudinal cut, a curvilinear form. 
The appearance of the kerfs indicates that the lateral longitudinal inei- 
sion through a part of its length, the anterior transverse incision for a 
short distance, and both the central incisions, completely penetrated 
the inner table and invaded the intracranial tissues, but that in gen- 
eral the incisions were not carried entirely through the bone, and some- 
times only into the diploe, when the operator had recourse to an 
elevator. The marks indicate also that the elevator was inserted over 
the interior angle of the medio-posterior button (or quarter button) in 
such manner as to lift the inner edges of one or more of the other but- 
tons, and that pressure was exerted until they were broken out, singly 
or together, and until the corner of the remaining button was chipped 
or spalled off under the strain. At this stage the operation was aban- 
doned, the sharp edges of broken bone being left untouched; and there 
is no trace of reparative growth. 
There is nothing to indicate certainly whether the operation was late 
ante-mortem or early post-mortem, further than the abandonment of 
an incomplete operation suggesting death in the hands of the operator, 
and the cuts extending through the bone and into the cerebral tissues 
in such manner as probably to produce fatal results; nor are there 
traces of antecedent lesion. 
There is a depression about the center of the right half of the frontal 
bone, apparently the record of a blow received long before death. 
CRANIUM 5 
(Plates X, XI) 
This specimen is one of the largest in the collection; it is in good 
condition, having been taken from a mummified body in a fair state 
of preservation. The sutures and teeth indicate approaching maturity. 
The skull is strong and symmetric, though thinner than the average 
