part 1] secojS^d skull from the piltdown gravel. 5 



and internal features are opposite, as in modern man. It is there- 

 fore clear that, in the skull represented by this new fossil, the 

 muscles of the neck must have extended farther up the occiput 

 than is usually the case. Such an upward extension of the neck- 

 muscles is already known in Neanderthal man, where it is supposed 

 to be correlated with the support of a heavy face ; and it may be 

 that in still earlier man the condition was variable, perhaps even 

 different in the male and in the female. If this were so, there 

 would be no reason to hesitate in referring the fragment now 

 described to Eoanthropus dawsoiil. 



The followmg are some measurements of thickness of the new 

 occipital bone, compared with that of JEoantliropus previously 

 described : — 



New fossil. Eoantliropus. 



Greatest thickness 17 mm. 20 mm. 



Thickness at internal protuberance ... 16 mm. 20 mm. 



Thimiest part of cerebellar wall 4 mm. 4 mm. 



The tooth, discovered by Mr. Dawson in the same locality as the 

 two pieces of bone, is a left first lower molar (PI. I, figs. 4 «-4 e) 

 agreeing very closely with that of the original specimen of Eocm- 

 tliropus dawsoni, but more obliquely worn by mastication. It is 

 equally well fossilized, and stained brown with oxide of iron in the 

 usual manner. The difference in the mode of wear can be seen in 

 its anterior end-view (4 e) when this is compared with that of the 

 original specimen (fig. 5). The tooth, as before, is elongated 

 antero-posteriorly, and its grinding surface (fig. 4^. a) lacks any 

 well-defined cruciform fissure, its central area being an irregular, 

 nearly smooth depression. Of its two inner cusps, the anterior is 

 the larger, and must have been more elevated than the posterior 

 cusp (its worn apex exposing a small triangular area of dentine, 

 while the latter is still covered with enamel). Both the outer cusps 

 are worn down to the dentine, the anterior exposing a slightly larger 

 area than the posterior cusp. The small fifth cusp behind is, as 

 usual, nearest the outer bordei-, from which it is visible in side 

 view (fig. -iZ*). It is also worn down so as to expose a very small 

 area of dentine. Between this, the postero-internal cusp, and the 

 posterior border of the tooth, the crown (fig. 4 a) is slightly marked 

 by a small transversely-extended depression. In outer view 

 (fig. 4/;) and inner view (fig. Ic), the depth of the crown is well 

 seen, and the two cusps are clearl}'- separated by a fissure. At 

 both ends of the tooth (4 d, 4 e), a pressure-scar is distinguishable. 

 The two roots, of which, only the upper portions are preserved, are 

 separate nearly as far as the neck of the tooth, which is but 

 slightly constricted. 



If the new tooth be compared with the corres])onding molai's of 

 a Melanesian (figs. Qa-Qe), a Tasmanian (figs. 7 a-7 d), and a 

 Chimpanzee (figs. 8«-8e), of approximately the same size, it will 

 readily be recognized as essentially human. In the considerable 



