In view of the stimulating discoveries made by Messrs. Schwantes and Rust in the districts of Hamburg and Kiel, I am prompted to write a preliminary note on two Mesolithic ‘floors’ recently discovered in the Ebbsfleet Valley, west of Northfleet, on the right bank of the Lower Thames. The horizons in question are located in a stoneless calcareous silt containing shells of both land and freshwater types. Subsequent erosion phases have considerably denuded the silt, which, at the present time, is overlain by some 6 ft. of alluvial deposits. The marked differences between the implements of the lower and upper ‘floors’ are best summarized as under:

1. The artifacts from the lower ‘floor’ are invariably patinated blue or white, whilst those from the upper ‘floor’ are always in an unaltered condition.

2. The blades from the lower ‘floor’ are much longer and broader than are those from the upper ‘floor’; some of the former attain 7½ in. in length (figs. 1, 2, 3, 4, and 5).

3. Core-scrapers are not present in the lower ‘floor’ though of common occurrence in the upper ‘floor’.

4. The gravers from the lower ‘floor’ (figs. 6 and 7) approximate more closely to those of Upper Palaeolithic times than do the examples from the upper ‘floor’ (fig. 8).

5. Though none has so far been recovered from the lower ‘floor’, the upper ‘floor’ has yielded shouldered points (figs. 9 and 10), a characteristic form in the Hamburg culture.