EARLY MAN Hill, somewhat resemble the latter and are wholly different from those from Maid's Cross Hill. Of implements from Portway Hill a sufficient number has not been examined to learn their leading characteristics. This marked difference in the appearance of implements found in gravels relatively near to one another points to the gravels having been formed at quite different periods, the man whose implements are found in the later gravels having appeared and occupied the country after his predecessors' handiwork had all been swept down and buried in the earlier gravels. Which then of the two gravels, the Warren Hill or the Maid's Cross Hill, is the earlier ? This question will be discussed when the gravels and their contained implements have been examined in rather more detail. As has been seen, the Warren Hill gravels cap the southern end of the ridge where the little escarpment slopes rapidly down to the Lark Valley. Their upper surface lies at an average of about 70 ft. above the Ordnance datum and between 30 ft. and 40 ft. above the River Lark. They are certainly between 30 ft. and 40 ft. thick, and the base has never apparently been reached. They are soft in structure, with much sand. As before said, the river that gave rise to them ran at a right angle to the course of the present River Lark, which has washed away a considerable, probably the larger, portion of the original gravel. On the opposite side of the Lark Valley — here 2 miles wide — are gravels lying at about the same height as those of Warren Hill and containing flint implements of very similar types, which were probably continuous with the Warren Hill gravels. It has been pointed out that the predominant type of implement at Warren Hill is the ovate with sharp edges all round ; the Warren Hill ovate is indeed familiar to all collectors of flint implements. An interesting and rather surprising fact is that this sharp ovate is rarely found in the Thames Valley. This valley from above Oxford to the Nore teems with implemen- tiferous gravels, and many thousands of implements have come out of them. In the writer's collection there are some three thousand specimens from the Thames Valley ; yet amongst this large number there is only one sharp ovate at all comparable to those which occur in such large numbers at Warren Hill. A few ovate implements occur, but they are of wholly different type from the bulk of those in the Suffolk gravel. What does this mean ? It can hardly be a question of local distribution ; for, on the one hand, gravels within a very few miles of Warren Hill contain no larger proportion of sharp ovates than do those of the Thames Valley ; whilst, on the other hand, sharp thin ovates, strictly like those from Warren Hill, are found in various other parts of England, as well as in France and in other more distant parts of the world. It would seem therefore that in the Thames Valley gravels and in the Warren Hill gravel we are dealing with two very distinct periods. The Thames Valley Period is, it is true, represented, though only in a meagre degree, at Warren Hill ; whilst the Warren Hill Period is scarcely represented in the Thames Valley. French archaeologists divide their ' drift ' period into two main divisions ; one named from Chelles in the department of Seine et Marne, thence called Chelleen ; the other from St. Acheul near Amiens, whence called Acheuleen. The classification is a rough one only, but has been almost universally accepted. The Thames Valley implements belong in the main to the Chelleen ; the Warren Hill implements to the Acheuleen. There seems 239
