MR. BUSK ON VEDDAH SKULLS. 169 
2. Breadth, taken wherever it is found to be placed, sometimes 
higher, sometimes lower. (Fig. 2.) 
3. Height, measured from the level of the foramen magnum to 
the highest part of the vertex. 
4. The least frontal breadth, measured usually immediately be- 
hind the external orbital process (Lf, fig. 3). 
5. The greatest frontal breadth, measured at the point where it 
exists, which corresponds most usually with that where the tem- 
poral line crosses the coronal suture (9 f, fig. 3). 
6. The parietal breadth, measured between the centres of the 
parietal bones (y, fig. 3). 
7. The occipital breadth, taken between the external angles of 
that bone (fig. 3). 
These last four measurements represent, however, only the chords, 
as it were, of the respective arcs above them; the arcs themselves 
are roughly estimated by the distance over each are from the 
middle of one external auditory opening to that of the other; and 
these measures may be termed, 
8. The frontal transverse are. 9. The vertical transverse arc. 
10. The parietal _,, ~,., 1. The oceynial. .,, 5 
The directions in which they are taken, by means of a graduated 
tape, are shown in the dotted lines fv, p, 0, in fig. 1. But in 
order to render the measurements of the three regions still more 
complete, it is necessary to ascertain, 1st, the length in an antero- 
posterior direction of each region, and, 2nd, the perpendicular 
depth, as it were, of the three cerebral lobes. The latter object is 
attempted by measuring the distance between a point correspond- 
ing with the pons Varolii to the surface of the skullina straight or 
radial direction ; and these measures are thus taken:—If a thin 
wire be passed straight through the middle of the auditory open- 
ing, and made to perforate the inner wall of the tympanun, it will 
enter the cavity of the cranium by the internal auditory opening, 
and of course pass out on the opposite side in the same way. In 
doing this, it would pass pretty nearly through the centre of the 
pons Varolit. Now, if an instrument be so constructed as to have a 
conical plug capable of being introduced into each of the external 
auditory openings, and fitted to move up and down on the branches 
of an instrument constructed upon the plan of a shoemaker’s gauge, 
the distance from the central point in question = the centre of the 
pons will be measured, including the thickness of the cranium, by 
the distance of the centres of the plugs from the stem of the in- 
strument, when that is made to touch any part of the periphery 
LINN. PROC.—ZOOLOGY, VOL. VI. 12 
