the Fossil Trees found at St. Helen's. 249 



too highly eulogized, since every discovery connected with this 

 fossil renders the value of the description more appreciable. 



The authors of the Fossil Flora have represented, in the 

 31st plate of their valuable work, what they term a "nearly 

 perfect specimen " of Stigmaria. This specimen, which was 

 obtained from the roof of one of the Newcastle coal seams, 

 shows only the under side; the central part, like the large tree 

 already described, was concave, " the whole surface being co- 

 vered with wrinkles, which, when attentively examined, were 

 seen to be caused by depressed semicircular spots, compactly 

 arranged in a spiral manner, in the centre of which is a round- 

 ish scar, to which a little fine coaly matter adheres." From 

 this centre the arms radiate, bifurcating as they increase in 

 length, and becoming covered with the characteristic tuber- 

 cles of Stigmaria, Having fibrils attached as they receded from 

 the centre. Two other individuals occurred in the same roof, 

 but the authors state " that the upper part of the centre itself 

 was too much damaged, to have its structure made out." From 

 an examination of these specimens they were induced to con- 

 clude " that Stigmaria was a prostrate land-plant, the branches 

 of which radiated regularly from a common centre, and finally 

 became forked." What the nature of this centre was, the 

 authors declare to be difficult to conjecture, but they conceive 

 it to have been dome-shaped, a form which probably resulted 

 from the plant growing upon a hillock. The succulent nature 

 of Stigmaria they infer from its commonly occurring in a com- 

 pressed state, and also from the eccentricity of its woody axis, 

 -when this is traceable, which also shows it to have been of a 

 dicotyledonous nature. 



From the great regularity of the tubercles which cover the 

 radiating portions of the plant, the authors are led to suppose 

 that they were the base to which leaves were attached, and 

 hence they reject the conclusion of Steinhauer, that they were 

 the parts from whence the roots emanated. The same cir- 

 cumstance which led them to infer the succulency of the ra- 

 diating parts, viz. their compressed state, also induced them 

 to suj)pose that what they termed leaves were of a similar cha- 

 racter. From their examination of the whole characters, the 

 authors came to the conclusion that the Stigmariae were allied 

 to the Euphorbiacese or Cacti. 



The reliance on the part of these authors on the perfection 

 of their specimen, which appears to have been sufficiently im- 

 perfect entirely to mislead them, has been the cause of many 

 errors having been propagated respecting Stigmaria. In the 

 first place, there appears to have been no evidence upon which 

 they were able to form any opinion as to the nature of the 



