266 Antediluvian Zoology and Botany. 
Wood, properly so called, is more or less abundant in the 
higher secondary strata. In none are they of more interest- 
ing character than in the Portland limestone, where enormous 
silicified trunks are fr equently discovered. Woody stems of 
dicotyledonous trees appear in the lias. The tertiary beds 
contain trunks and branches of trees, which are perforated by 
the Teréedo antenatite (Fistulana personata). In the London 
clay so extensively have their ravages prevailed, that it is rare 
to find any fossil wood free from them, and numerous instances 
are observed where the original mass has been almost entirely 
occupied by congeries of these animals. Fossil woed, per forated 
by the genus Philas, has been discovered in the ferruginous or 
lower green sand. 
Leaves and fragments of arborescent plants occur in the 
calcareous laminated sandstones near Hastings, and also in 
Tilgate Forest. ‘They form a species of coal, or Surturbrand, 
in the plastic clay beds at Alum Bay, at Newhaven, and Corfe 
Castle. 
Fruit and seed-vessels occur in the Yorkshire oolitic coal 
shales, and abundantly in the London clay at Sheppy; but the 
number of species has been there greatly exaggerated, owing 
to the fancied resemblance which some of the pyritous con- 
cretions bear to organic forms. ‘Those of undoubted vegetable 
and terrestrial origin are, however, extremely abundant, and 
appear to be closely allied to genera now existing in tropical 
regions. Seven hundred species are said to have been col- 
lected, by one individual, from the beach at the foot of Sheppy 
cliffs. On careful examination this number will be found 
exceedingly over-rated, and it may probably be reduced to 
about twenty species. ( fg. 52.) 
Seed-vessels from Sheppy of the natural size. 
