When we turn from the great Siberian continent, which, anterior to its elevation, was the chief abode of the mammoths, and look to the other parts of Europe, where their remains also occur, how remarkable is it that we find the number of these creatures to be justly proportionate to the magnitude of the ancient masses of land which the labours of geologists have defined! Take the British isles, for example, and let all their low, recently elevated districts be submerged; let, in short, England be viewed as the comparatively small island she was when the ancient estuary of the Thames, including the plains of Hyde Park, Chelsea, Hounslow, and Uxbridge, were under the water; when the Severn extended far into the heart of the kingdom, and large eastern tracts of the island were submerged,--and there will then remain but moderately-sized feeding-grounds for the great quadrupeds whose bones are found in the gravel of the adjacent rivers and estuaries. This limited area of subsistence could necessarily only keep up a small stock of such animals; and, just as we might expect, the remains of British mammoths occur in very small numbers indeed, when compared with those of the great charnel-houses of Siberia, into which their bones had been carried down through countless ages from the largest mass of surface which geological inquiries have yet shown to have been _dry land_ during that epoch. The remains of the mammoth, says Professor Owen, have been found in all, or almost all, the counties of England. Off the coast of Norfolk they are met with in vast abundance. The fishermen who go to catch turbot between the mouth of the Thames and the Dutch coast constantly get their nets entangled in the tusks of the mammoth. A collection of tusks and other remains, obtained in this way, is to be seen at Ramsgate. In North America, this gigantic extinct elephant must have been very common; and a large portion of the ivory which supplies the markets of Europe is derived from the vast mammoth graveyards of Siberia. The mammoth ranged at least as far north as 60°. There is no doubt that, at the present day, many specimens of the musk-ox are annually becoming imbedded in the mud and ice of the North-American rivers. It is curious to observe, that the mammoth teeth which are met with in caves generally belonged to young mammoths, who probably resorted thither for shelter before increasing age and strength emboldened them to wander far afield. THE RHINOCEROS AND HIPPOPOTAMUS OF ENGLAND.