206 STUDIES IN FOSSIL BOTANY 



these trees found in a sandstone quarry, of Coal-measure 

 age, at Clayton, near Bradford, in Yorkshire. The actual 

 stump of the tree is here 4 feet 4 inches in diameter, 

 while the whole specimen, including the forked roots, 

 is almost thirty feet across. This gigantic fossil is now 

 set up in the Museum of the Owens College at 

 Manchester, and affords a striking example of the 

 scale of Palaeozoic vegetation. Fragments of other 



Fig. 85. — Stump and roots ( = Stigjnaria ficoides) of a Lycopodlaceous tree from the 

 Coal-measures. For description, see text. After Williamson. 



specimens, which must have been about twice the size 

 of this one, were found at the same time. 



Before going further into the question of the habit 

 of the Sigillarian trees, it will be necessary to give some 

 account of the characteristic superficial markings, by 

 which the genus is commonly recognised, and according 

 to the variations in which, the so-called " species " are 

 distinguished. 



Sigillaria, like Lepidodendron, is characterised by the 

 form and arrangement of the leaf-scars, left on the 



