Pleistocene Deposits around Cambridge. 699 



trustworthy index of antiquity, and modifications of the classification 

 proposed by W. Penning and A. J. Jukes-Browne are indicated. 



The author suggests the following chronological sequence, in 

 descending order :- — Feet. 



(1) Barnwell Station Beds 20 



(2) Newer Downing- Site Beds 35 



(3) Newer Barnwell Village Beds 45 



(4) Huntingdon Road Clays 70 



(5) Observatory Beds 85 



(6) Covbicula Gravels (Barnwell village, etc.) ... 30 



The figures on the left give the approximate height above sea-level. 



It is believed that Nos. 6 and 5 were formed during a period of 

 aggradation, and 4-1 during one of subsequent erosion with minor 

 aggradation ; but it cannot be conclusively proved that 6 and 3 are 

 of different ages, although the deposition of the beds 6 below those 

 of series 3, where they occur together, and the occurrence of 

 Hippopotamus and Bel 'grand ia marginata with Corbicula suggest 

 an early date for these Corbicula -hewing beds. 



Taking the beds in the order of reputed age, the following- 

 observations are noted : — 



Chellean implements have been found at low levels at Barnwell 

 and Chesterton, and may belong to the beds 1. The Observatory 

 Beds have yielded abundant implements of Chellean, Acheulean, 

 and early Mousterian types, the last-named apparently in deposits 

 later than those containing the two first-named. Unfortunately 

 mollusca and mammalia are very rare in these beds. The Hun- 

 tingdon Road Clays require much further work, as on\j poor 

 exposures have hitherto been found, and it is not clear that they 

 are newer than the Observatoiy Beds. 



The beds referred 'to the Newer Barnwell Village Series contain 

 abundant remains of the mammoth, woolly rhinoceros, and fairly 

 numerous horse-bones. Implements associated with them suggest 

 an Upper Palaeolithic age. 



The Newer Downing Site Beds have yielded a cold molluscan 

 fauna. The}" are probably somewhat earlier than the Barnwell 

 Station Series, which has furnished a similar molluscan fauna, and 

 also an Arctic flora, the plants of which were identified by the late 

 Mr. Clement Reid. Reindeer occurs in these beds. 



The paper is chiefly a record of facts, but it is intended to be 

 preliminary to a detailed survey of the Pleistocene deposits of the 

 Great Ouse Basin, which are so important as throwing light upon 

 the relationship of the Palaeolithic beds to the glacial accumulations, 

 and also to the marine beds of March and the Nar Valley. 



Appendix I, on the Non-Marine Mollusca, is supplied by Alfred 

 Santer Kennard, F.G.S. and B. Barham Woodward, F.L.S., F.G.S. 



Lists are given of the non-marine mollusca from the various 

 sections, with their degrees of frequency. These lists are based on 

 examination of old collections and on a large amount of new 

 material. Noteg are appended on some of the species, and con- 

 clusions as to the ages of the Cambridge gravels are given, based 

 on the molluscan evidence. 



Appendix II, on the Implements, is supplied by Miles C. Burkitt, 

 M.A. 



