110 



has been removed, the surface presents a layer of matted vegetable matter, 

 seemingly composed of roots. This seam is in places several inches thick ; 

 on the under side roots descend into the subjacent clay, showing that it has 

 been an old surface of plant-gi-owths. The stools of trees project slightly 

 above the level of this old land surface, and upon it He the trunks of trees. 

 In every instance examined, the surface of plant-growths was intei-posed 

 between the prostrate trunks and the underljing blue clay. The roots and 

 long leaves seemed to belong to an Iris such as the common 'yellow flag.'" 



The above is characterised as "Area depressed below sea 

 level." 



IV. The blue mud-deposit occuring next " is a very tenacious 

 mass, resisting the action of the sea. From the abundance 

 of diffused vegetable matter it has the appearance of being of 

 fresh- water origin. It might seem at first sight, as indeed it 

 did to Sir H. De la Beche, that the trees of the submerged 

 forest had grown in this blue mud, from the manner in which 

 they stand out of it ; but the mud-deposit surrounds the stools 

 of the trees, which never send roots into it ; and wherever the 

 mud has been removed, the trees are seen to be rooted in the 

 beds beneath. The accumulation of the mud has been subse- 

 quent to the forest growth. The uniform level at which the 

 trees have been cut off may, perhaps, indicate the level of the 

 water which deposited the blue mud, and killed the trees at the 

 same time." Here, then, we have " accumulation of fresh water 

 mud, resulting probably from a depression of the level of the 

 land." 



V. With regard to the submerged forest, we find that " the 

 interval left bare by the tide may, under favourable circum- 

 stances, be seen studded thickly with the stools of large trees — 

 some bare, some covered by a thick growth of sea-weed, some 

 just projecting above the mud beds. Some are of large size — 

 one measured two feet in diameter. The largest trees were 

 the oaks, which may be distinguished by the black colour of the 

 wood ; others when spHt open are red, probably alders ; from 

 their dimensions both must have grown under favourable con- 

 ditions. The j)rostrate trunks lay generally N.W., S.E., or away 

 from the opening of the valley ; they had been broken off 



