Plate XIII. FILICALES: SPHENOPTERIDAE 



Here belong such leaf impressions as might have grown 

 on true herbaceous fern plants, on tree-ferns, and on so- 

 called seed-ferns or Cycadofilicales. The latter are an ex- 

 tinct type of Gymnosperms with fern-like foliage and 

 cycad-like fructifications. They formed a link between 

 ferns and cycads in evolution. In this publication all fern- 

 like leaves are listed under Filicales and all Cycadofilicales- 

 seeds under Cycadofilicales. Stems of true ferns were found 

 and are pictured in this bulletin under the generic names 

 Megaphyton and Ptychopteris. (See Plates XIII to XIV.) 



1. Palmatopteris furcata (Brongniart) Potonie, from Braidwood, 



U C Coll. No. 32020. 



2. Sphenopteris gracilis Brongniart, from Mazon Creek, U C Coll. 



No. 32021. 



3. Sphenopteris capitata White, from Braidwood, U C Coll. No. 



32022. 



44 



