J. SMITH ON THE GENERA OF FERNS. 59 



versely combined veinlets which are sporangiferous on their 

 combined apices or line of junction. Sori round, oval or 

 rarely oblong-linear, transversely uniserial, or multiserial. — 

 Fronds simple, entire, pinnatijid or pinnate, "membranous or 

 coriaceous, smooth or squamiferous. Sori sometimes more obvi- 

 ously arranged in oblique roivs, between each tivo of the primary 

 veins. 



* Pleopeltis. 



Fronds generally coriaceous and squamiferous. Veins usu- 

 ally internal. Sori uniserial, often oval, or oblong and large, 

 and at first covered with the scales of the frond. 



Examp. I. P. lanceolatum; {Linn.) 2. P. salicifolium ; 

 {Willd.) 3. P. serpens; {Linn.) 4. P. percussum ; {Cav.) 

 5. P. macrocarpum; {Willd.) 6. P. elongatum; (Grammi- 

 tis, Sw.) 7. P. angustum; (Pleopeltis, Humb.) 8. P. 

 ensiforme ; (Thunb.). 



** Phlebodium verum. 



Fronds usually large, pinnatifid or pinnate, smooth, or 

 glaucous. Veins external. Sori transversely uniserial or 

 multiserial, round. 



Examp. 9. P. aureum; {Linn.) 10. P. decumanum ; 

 {Willd.) 11. P. areolalum ; {Willd.) 12. P. latum ; (J. Sw.) 

 — Illust. Schk. Crypt, t. T. Hook. gen.Jil. ined. 



Obs. The habit of a few of the species of this genus is ana- 

 logous to Goniophlebium, but from which Phlebodium differs 

 by having the lower venules combined, and the costal areole 

 therefore sterile, the sori being produced on the apex or con- 

 fluent point of two veinlets which terminate in the exterior 

 rows of areoles, each areole producing a single sorus. 



In Phlebodium elongatum, and another undescribed species, 

 the fertile areoles are lengthened transversely as also the sori, 

 which latter is to be accounted for by the fertile veinlets 

 being distant and connected by an elongated sporangiferous 

 receptacle, which structure presents a very marked character, 

 but as their habit does not differ from others of that section^ 



