Vol. 69.] THE HUMAN SKTJLL, ETC. FROM PILTDOWN. 125 



The largest continuous portion of the brain-case comprises the 

 left side of the frontal and parietal regions, extending upwards 

 just over the middle line both in the hinder part of the frontal 

 and near the larabdoid suture of the parietal. The position of the 

 middle line is indicated by the impression of the longitudinal 

 sinus on the cerebral face of the bone at both these points, and by 

 a slight longitudinal ridge along the outer face at the hinder 

 end of the parietal region. The left temporal bone is nearly com- 

 plete and beautifully preserved, lacking only the upper portion of 

 the squamous wing. At one point it articulates perfectly with 

 the squamous suture of the parietal, and the impressions of the 

 meningeal vessels of the parietal are directly continued on its 

 cerebral face, so that this bone can be assigned to its true position. 

 The left side of the brain-case thus formed has no point of contact 

 with the other two pieces of bone ; but one of these is the greater 

 part of the right parietal, extending from the lambdoid suture 

 behind to the anterior end of the squamous suture in front, and so 

 completely symmetrical with the left parietal that its exact 

 position can be determined by measurement. The fourth piece of 

 the brain-case is the middle region of the occipital bone, with a 

 trace of the border of the foramen magnum below and a short 

 extension as far as the lambdoid suture in one part of the right 

 side above. The occipital and the right parietal thus come into 

 •direct contact for an extent of about 20 mm. The greater 

 portion of the brain-case may, therefore, be reconstructed without 

 any hypothetical restoration : the only serious deficiency being the 

 middle portion of the frontal region above the supraorbital ridge. 

 Such a reconstruction, with a justifiable amount of modelling, has 

 been skilfully made by Mr. Frank 0. Barlow in the Palasontologieal 

 Laboratory of the British Museum, and this is shown from four 

 aspects, with a longitudinal median section, in PL XVIII, 

 figs. ]-4, and text-fig. 3 (p. 126). The actual pieces of bone are 

 indicated by a dark tint, and the modelled portions by a lighter 

 tint, while the hypothetical part is white. 



As seen from above (norma verticalis, PI. XVIII, fig. 1), the 

 cranium is very wide posteriorly, measuring 150 mm. across its 

 widest part j nst behind the malar arch, and tapering forwards to a 

 slight, constriction behind the supraorbital ridge, where its width 

 is 112 mm. The total length from the middle of the supraorbital 

 ridge (glabella) to the external occipital protuberance (inion) is a 

 little uncertain, owing to the hypothetical restoration of the middle 

 of the frontals, but it measures probably 190 mm. The cephalic 

 index may, therefore, be regarded as 7S or 79. Owing to the 

 constriction of the frontal region, the malar arch is visible from 

 above. 



In anterior view (norma facialis, PL XVIII, fig. 2), the relative 

 narrowness of the frontal region is well shown, and the roof is 

 seen to rise to the vertex at the widest part of the skull. In side 

 view (norma lateralis, PL XVIII, fig. 3), this upward slope is still 

 better seen, and the steeply-curved frontal contour is especially 



