AO PRIMITIVE TREPHINING IN PERU [ETH. ANN. 16 
The specimen illustrated in figure a, plate xxy11, displays two aper 
tures, both of somewhat doubtful character. One is an elongated slot, 
the outline and sharp edges of which suggest the use of a metal instru- 
ment; but the method in which the operation was performed can not 
be determined from engraving or photograph. The cranium repre- 
sented in figure ) exemplifies a mode of operation distinct from any of 
those indicated by the Muniz collection. In one case there are three 
rather small perforations placed in the form of a triangle. The perfora- 
tions suggest the use of a drilling or boring instrument, perhaps simi- 
lar to the brima used by the Kabyle, and their arrangement suggests that 
the drilling was followed by the use of a strong elevator and the break- 
ing out of the fragment described by the perforations, also after the 
manner of the Kabyle. The large aperture made above the right orbit 
in the same specimen would appear to have been produced in this way. 
In this manner, too, the huge aperture in the specimen shown in figure 
a, plate XXxv1, might have been produced. The reproduction suggests 
the employment of rude metal instruments, although the operation is of 
no higher order than those revealed in the Muniz collection, and although 
the drilling and elevating might easily have been effected by stone per- 
forators and elevators of bone or wood. The operations represented in 
figure b and the elongated opening shown in figure @ (plate xxvit) 
reveal no indications of subsequent growth, and may accordingly have 
been late ante-mortem or post-mortem. 
The figures ¢ and d, in plate XXVII, represent two approximately cir- 
cular operations, comparable with several of those revealed in the 
Muniz series. Viewed in the light of these examples, it would appear 
that both were performed by means of somewhat irregular curved inci- 
sions, followed by the use of the elevator, and that the margins were 
subsequently beveled by rasping or scraping; it would appear also that 
both individuals long survived the operation, as indicated by repara- 
tive growth and rounding of surface, and the partial obliteration of the 
diploe. 
CRANIUM 14 
(Plates XXVIII, XXLX) 
This specimen is a mummified head, with most of the scalp and facial 
integument and some of the hairremaining. The mature development 
of the teeth and the condition of tlhe small portion of the sutures visi- 
ble indicate maturity; the hair is not gray. The tendons are well 
developed; the skull is thinner than the average for the collection, 
measuring about 3 mm. at the point of operation. 
The single incomplete operation displayed by the specimen is remark- 
ably instructive. It was located by a depressed fracture in the left side 
of the frontal bone, centering 45 mm. above the orbit, and extending 
just to the coronal suture; in this fracture a section of both tables 15 
by 20 mm. was forced inward, hinging at the left, but completely 
