PRIMAEVAL MAN IN THE VALLEY OF THE LEA.
135
incorporated with sand ; the bed of the brook at E is filled with fine
sand, stratified and perfectly horizontal. Above this, at F, is "warp
and trail"; and at the top at G, surface humus. It will be noticed that
the "warp and trail" has ploughed its way through the brook and its
banks, which brook had been previously filled up with fine sand. A few
yards off, in the direction of H, the bank of the brook was again
exposed, untouched by "warp and trail," and on this bank a beau-
tiful unabraded Palaeolithic implement was found, with numerous
keen-edged flakes. The point J, is the lowest point in the Bayston
Road to this day. At this point the London clay is about twenty-
seven feet from the surface.
London clay comes to the surface close by towards the north-west.
Nothing is more common than to see seams and rolled blocks of this
clay in the sand and gravel, and also in the "warp and trail ;" some-
times implements and flakes and vegetable remains may be seen
sticking in this transported clay.
Fossil Shells.
In my paper published in vol. iii. of the "Transactions of the
Essex Field Club," p. 119, I enumerated 16 species of fossil shells
then known to me as belonging to the Lea Valley: since that time I
have detected 29 others, making 45 in all.
List of the fossil-shells of land and fresh water molluscs found
in the Palaeolithic sand of north-east London.
1. Corbicula fluminalis, Mull.
2. Splaerium corneum, Linn.
3. Pisidium amnicum, Mull.
4. „ fontinale, Drap. ; var.
henslowana, Jeff. ; var.
pulchella, Jeff.
5. ,, pusillum, Gmelin.
6. Unio tumidus, Phil.
7. ,, pictorum, Linn.
8. Bythinia tentaculata, Linn.
9. Hydrobia marginata, Mich.
10. Valvata piscinalis, Mull; var.
subcylindrica, Jeff.
11. ,, cristata, Mull.
12. Planorbis nitidus, Mull.
13. „ nautilens, Linn.
14. ,, albus, Mull.
15. „ marginatus, Drap.
16. ,, glaber, Jeff.
17. ,, spirorbis, Mull.
18. ,, carinatus, Mull.
19. ,, complanatus, Linn.
20. ,, contortus, Linn.
21. Limnaea peregra, Mull.
22. Limnaea auricularia, Linn.
23. „ stagnalis, Linn.
24. ,, palustris, Mull.
25. „ truncatula, Mull.
26. ,, glabra, Mull.
27. Ancylus fluviatilis, Mull.
28. ,, lacustris, Linn.
29. Succinea putris, Linn.
30. Zonites radiatulus. Ald.
31. ,, nitidus, Mull.
32. ,, crystallinus, Mull.
33. Helix aculeata, Mull.
34. ,, nemoralis, Linn.
35. ,, arbustorum, Linn.
36. ,, rufescens, Penn.
37. „ concinna, Jeff.
38. ,, hispida (?), Linn.
39. ,, pulchella, Mull.
40. Pupa umbilicata, Drap.
41. ,, marginata, Drap.
42. Clausilia biplicata, Mont.
43. Cochlicopa lubrica, Mull.
44. Achatina acicula, Mull.
45. Carychium minimum, Mull.