22 MORPHOLOGY OF GYMNOSPERMS 



The foliage of Heterangium and of Lyginodendron has been shown 

 to be of the Sphenopteris type, one of the great and heterogeneous 



Fig. I •] .—Sphenopteris elegans (probably foliage of Heterangium Grievit) : part of 

 frond; X§.— After Stdr (7). 



frond genera of the Paleozoic, in general habit like Asplenium (82). 

 The foliage of Heterangium Grievii is probably Sphenopteris elegansj 

 the leaf being large and stalked, several times pinnately compound^ 

 and with numerous small leaflets (fig. 17). Scott (24) describes 



