FERNS— FRONDS 271 



The more essential characters are indicated by 

 italics. 



Among recent Ferns this form of frond is best re- 

 presented among some of the Tree-ferns (Cyatheaceae). 

 Fig. 1 07, illustrating the species P.^Dactylothecd) 1 dentata, 

 will give a sufficient idea of the habit of a Pecopteris 

 frond, though the true affinities of the plant are 



Fig. 107. — Pecopteris (Dactylotheca) dentata. Part of a frond, with the matrix. 

 Reduced. From a photograph by Mr. W. Hemingway. 



doubtful. There is good evidence that some of these 

 fronds were really borne by Tree-ferns of the Carbo- 

 niferous epoch, belonging, however, to a family quite 

 distinct from that which includes our recent arborescent 

 Ferns. A considerable variety of fructifications has 

 been found in connection with fronds of the Pecopteris 

 type ; in many cases the reproductive characters point 



1 The second generic name, Dactylotheca, is based on the fructification, 

 which happens to be known in this species. It may be Pteridospermous 

 (see Fig. 109, C). 



