718 



THE WONDERS OF GEOLOGY. 



Lsct. VII 



form and disposition of the fronds and pinnules. The 

 JPecopterls, a genus containing fifteen British species, is 

 found every where {Licjn. 158, 159).* 



1 3 2 



LlGN. 160. — SlGILLARI^, AS D FERN, FROM THE COAL-MEASURES. 



(One-fourth the natural size. ) 



Fig. 1. Sigillaria Voltzii, from the anthracite of Baden; a the external 

 surface ; b the inner surface, a portion of the outer bark being 

 removed. 



— 2. Sigillaria Sillimani : from the coal-mines of Pennsylvania. 



— 3. Pecopteris Miltoni; a specimen showing the young frond coiled up 



like a crosier. 



36. Sigillaria. — Among the most common and striking 

 objects that arrest the attention of a person who visits a 

 coal-mine for the first time, and examines the fossil remains 

 profusely scattered around him, are long flat narrow slabs 

 of a coaly substance, having the surface fluted longitudi- 

 nally, and uniformly ornamented with rows of deeply 

 imprinted symmetrical figures, disposed with great regu- 

 larity. These relics are the flattened stems, covered by 

 the bark or rind, of trees of large size : the markings on 

 the surface being the scars left by the separation of the 

 petioles or leaf- stalks. f The name Sigillaria has been 



* See Medals of Creation, pp. 111—129, for figures and descrip- 

 tions of fossil ferns. 



f The markings left on a cabbage-stalk by the removal of the 

 leaves are of a similar nature. 



