CHAPTER VII 



LYCOPODIALES — continued 



Sigillaria and Stigmaria ; Lycopoditeae 



I. Sigillaria 



We now come to the great genus Sigillaria, one of the 

 most extensive and important groups of Palsezoic plants, 

 and one of those of which the affinities have been most 

 keenly discussed. In geological range the Sigillariae 

 are somewhat more restricted than the Lepidodendra ; 

 they have not been detected with certainty below the 

 rocks at the base of the Carboniferous formation, and 

 scarcely extend above the Permian ; they attain their 

 maximum in the Middle and Upper Coal-measures. 



I. Habit and External Characters. — The Sigillariae 

 must have been among the largest trees of the Palaeozoic 

 forests. A trunk of Sigillaria reniformis, found near 

 Saarbrlicken, in Germany, in situ, was 6 feet in diameter 

 at the base, where its roots were attached. This trunk 

 was only 1 8 feet high, diminishing towards the top to a 

 diameter of about a foot. Other gigantic specimens 

 have a very different form. M. Zeiller 1 describes a 



1 Bassin houiller de Valenciennes, flore fossile, p. 512. 

 204 



