STIGMARIA 239 



long branch. This specimen appears to be the largest 

 Stigmaria which has been found in actual connec- 

 tion with the tree-stump to which it belonged ; 

 detached specimens have been described of much 

 greater length. 



Up to the year 1839 there seems to have been 

 no good evidence as to the nature of Stigmaria, though 

 the probability of its being the root of Sigillaria was 

 recognised by some investigators, as, for example, by 

 Brongniart. In 1839, during the construction of the 

 Manchester and Bolton Railway, the stumps of several 

 large fossil trees were discovered at Dixon Fold, with 

 four great dichotomous roots radiating from the base 

 of each trunk. The distinctive characters of these 

 trees and their roots,' however, could not be determined. 

 A few years later a number of similar trees were 

 found by Binney at St. Helen's and at Dukinfield, in 

 Lancashire. Their trunks showed the characteristic 

 Sigillarian markings, while the branches of the forked 

 roots bore the Stigmarian scars. 1 Thus the proof was 

 first given that Stigmaria is identical with the sub- 

 terranean parts of the Sigillarian trees, a conclusion 

 which has been confirmed by various later observations. 

 Subsequently, other specimens of Stigmaria were 

 found in connection with tree-trunks, which showed 

 the markings, not of Sigillaria, but of Lepidodendron. 

 Specimens of this kind were first observed in the 

 Coal-measures of Nova Scotia, by Richard Brown, 

 soon after Binney's discoveries in England, but there 

 was some doubt as to whether Brown's trees were 



1 See Williamson, "Monograph of Stigmaria ficoides," Palceontographi- 

 cal Society, 1886. 



