Reports & Proceedings — Geological Society of London. 43 



described by the first author. In the section exposed it is about 

 4 feet thick. It consists, for the greater part, of waterworn frag- 

 ments of Wealden ironstone and sandstone, with occasional pebbles of 

 chert, probably from the Greensand, and a considerable proportion of 

 Chalk flints, which are also waterworn, all deeply stained with oxide 

 of iron, and most of them tabular iu shape. The human skull was 

 originally found by workmen, broken up by them, and most of the 

 pieces thrown away on the spot. As many fragments as possible 

 were recovered by the authors, and half of a human mandible was 

 also obtained by the first author from a patch of undisturbed gravel 

 close to the place where the skull occurred. Two broken pieces of 

 the molar of a Pliocene type of elephant and a much-rolled cusp of 

 a molar of Madodon were also found, besides teeth of Hippopotamus, 

 Castor, and Equus, and a fragment of an antler of Gervtis elaphus. 

 Like the human skull and mandible, all these fossils are well 

 mineralized with oxide of iron. Many of the waterworn iron-stained 

 flints closely resemble the ' eoliths ' from the North Downs near 

 Ightham. Mingled with them were found a few Palaeolithic 

 implements of the characteristic Chellean type. The gravel at 

 Piltdown rests upon a plateau 80 feet above the River Ouse, and at 

 a distance of less than a mile to the north of the existing stream. 

 It appears to cover several acres, but at the same level on the opposite 

 (south) side of the river it is represented only by scattered flints. 

 Numerous iron-stained tabular flints, like those of the Piltdown 

 gravel, have been found in the basin of the Ouse between the Chalk 

 escarpment and Sheffield Park and between this escarpment and 

 Uckfield. As they are identical with the flints well known in the 

 plateau deposits of the North and South Downs, it may be assumed 

 that they have been derived from a plane formerly existing between 

 those two points. 



The human skull and mandible and the associated fossils are 

 described by the second author. The skull (which unfortunately 

 lacks the bones of the face) exhibits all the essential features of the 

 genus Homo, with a brain capacity of not less than 1,070 c.c, but 

 possibly a little more. It measures about 190 mm. in length from 

 the glabella to the inion, by 150 mm. in width at the widest part of 

 the parietal region ; and the bones are remarkably thick, the average 

 thickness of the frontals and parietals being 10 mm., while an 

 exceptional thickness of 12 mm. is reached at one corner. The 

 forehead is steeper than that of the Neanderthal type, with only 

 a feeble brow-ridge ; and the conformation of the occipital bone 

 shows that the tentorium over the cerebellum is on the level of the 

 external occipital protuberance, as in modern man. Seen from behind 

 the skull is remarkably low and broad, and the mastoid processes are 

 relatively small. The right mandibular ramus is nearly complete 

 to the middle of the symphysis, lacking only the articular condyle 

 and the upper part of the bone in advance of the molars. The 

 horizontal ramus is slender, and so far as preserved resembles in 

 shape that of a young chimpanzee (^Ajithropopithecus niger). The 

 lower symphysial border is not thickened and rounded, as in man, 

 but produced into a thin inwardly curved flange, as in the apes. 



