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so characteristic a feature in the contours of the 

 Inner Hebrides, arc portions of lava-floAvs, which in 

 the early days of the Tertiary period were poured 

 out over a wide area of land stretching from the 

 north-east of Ireland, through the Western isles of 

 Scotland, the Faroe islands, to Iceland and Greenland. 

 While in this northern region volcanic activity was 

 being manifested on a stupendous scale, a shallow 

 sea extended over part of what is now the south- 

 east of England in which was deposited a considerable 

 thickness of sedimentary material derived from the 

 neighbouring land. In this upraised sea-floor, known 

 as the London cl^y, which is exposed in the Isle of 

 Sheppey and in many other localities, numerous fossil 

 fruits and fragments of wood occur in association 

 with marine shells. The fact that many of the fruits 

 were ripe at the time of their entombment led some 

 eighteenth century writers to assign an autumn date 

 to the universal deluge. One of the Sheppey fruits 

 may be mentioned as an especially interesting sample 

 of the early Tertiary flora, namely the genus Nipa- 

 dites, so named from the very close resemblance of 

 the fossils to the fruits of the existing tropical plant 

 Nipa. Nipa frutlcaus, sometimes described as a 

 stemless palm because of the absence of the erect 

 stem which is usually a characteristic feature of 

 palms, grows in brackish estuaries of many tropical 

 countries (Fig. 5, A) : it has long leaves not unlike 



