60 J. SMITH ON THE GENERA OF FERNS. 



and which also have a tendency to produce oblong sori, ihey 

 cannot with propriety be separated. 



This genus, as now characterized, contains the original and 

 other species of the genus Pleopeltis of authors, which de- 

 pended for its character as a genus entirely on the sori being 

 furnished with numerous scales similar to an indusium, but 

 as these scales are common to the whole surface of the frond, 

 they therefore, according to my view, cannot be considered 

 of generic value alone; but as the species which I have 

 placed under the section Pleopeltis are of a different habit 

 from what I have termed true Phlebodium, it might therefore 

 be no great impropriety in considering tiiem as two distinct 

 genera. In some few of the species of the first section, the sori- 

 ferous veinlets are sometimes very short or come from nearly 

 the opposite sides of the areole, which gives an appearance 

 as if the sori were seated on the angular anastomose of the 

 venules, similar to the following genus, with which the}' have 

 other points of affinity. 



21. Drynaria. Bory. R. Br. J. Sm. 



(Poiypodii sp. Auth. Dipteris. Reinw, Phymatodes. Presl. 

 Microsorum. Link. Anaxetum. Schoit.) 



Veins usually costaeform, parallel or flexuose. Venules com- 

 pound anastomosing, producing from their sides variously 

 directed, free, usually sterile veinlets, which terminate within 

 the areoles. Sporangia produced on the angles or points of 

 confluence of (generally) numerous veinlets. Sori round or 

 sometimes oblong, transversely uniserial, or in one or two 

 oblique rows between each two of the primary veins, or irreg- 

 ular. — Fronds from a few inches to two or three feet long, 

 membranous or coriaceous, smooth, simple, entire, pitinattjid 

 or pinnate, pinnts usually articulated with the rachis. Son 

 naked or squamiferous, superficial or deeply immersed, forming 

 protuberances on the superior side of the frond. 



Obs. This extensive genus difters from the preceding by 

 the more compound and zigzag anastomose branching of the 

 venation, and by the sori being produced on the angles or 



