414. Walter Keeping—The Upware and Potton Pebble-beds. 
was startled by news that Mammoths were still living, and that a 
Cossack had traced some to their haunts. This sensational news, 
I need not say, was not confirmed. 
I notice that Mr. Skertchly, in his recent work on the Fen 
district, in which he has embodied so much valuable and interesting 
information, has gravely suggested that it is possible Mammoths 
may have been living quite recently in Siberia, grounding his 
argument on the above-quoted passage of Bell. I need not say 
that no Russian naturalist holds such a view, and that the popular 
legends are undoubtedly the natural outcome of the remains of 
these huge beasts being found under such curious conditions. The 
nature of these conditions, and the very interesting light they throw 
upon the most recent geological changes in the Northern hemi- 
sphere, we will discuss in another paper. Here it will have sufficed 
to collect the evidence showing how very early and widespread was 
the knowledge of the existence of the Mammoth, and to report some 
of the curious legends which the indigenes of Siberia have built up 
out of it. . 
V.—ON THE INCLUDED PEBBLES OF THE Urprer Nrocomian SANDS OF 
THE SouTH-Hast oF ENGLAND, ESPECIALLY THOSE OF THE UPWARE 
AND Porron PEBBLE Beps.} 
By Watter Kerzpine, M.A., F.G.S., 
Lecturer on Geology in the University of Cambridge. 
T has often appeared to me that in working out the ancient physical 
features of the earth in former periods of its history, too little 
attention has been given to one simple set of evidences which are of 
wide-spread occurrence, and, frequently, of very clear and decided 
meaning. J refer to the included rock-fragments of conglomeratic 
deposits. An appeal to these fragments would, I believe, often 
bring out clearly-written facts of no small value for the elucidation of 
the nature of ancient sea-margins, as compared with the much- 
involved palzontological evidences with which we are made so much 
more familiar. 
Any particular rock exposed along the coast-line, or brought down 
to the sea by rivers, becomes more or less wide-spread along the 
shores and over the sea-bed as it is rolled into pebbles by the action of 
marine tides and currents, and scattered, it may be, by floating agents ; 
and thus a series of pebbles in geological deposits shows the nature 
of the old sea-cliffs and neighbouring lands, and may serve to prove 
the original physical continuity of deposits now completely isolated. 
Also a further interest attaches to these fragments as relics, scanty 
it may be, of those great masses of rock-formations which have been 
destroyed by the denudations of past ages. 
Bearing in mind these interests, a series of pebbles has been 
gathered together by Prof. Hughes and Prof. Bonney, myself, and 
other geologists from the Neocomian Pebble beds of Upware (near 
Cambridge), Potton (Beds), and elsewhere, the results of which are 
embodied in the following account. To Professor Bonney I am par- 
1 Read before the Cambridge Philosophical Society, May 3, 1880. 
