CHAEACTER3 OF TRIBES AND GENERA. 119 



Illust. Hook. Fil. Exot., t. 78 ; Hook. Gard. Ferns, t. 3 ; 

 Moore Ind. Fil., p. 15, A; J. Sm. Ferns, Brit, and 

 For., %. 19 ; Hook. Syn. Fil,, t. 8, fig. 60, cc.,dd.,ee. 



Obs. — This genus is disting-uished from Drymoglossum 

 by the fronds being aniform, and their contracted upper 

 portion bearing the sporangia, which become confluent, 

 and which led some authors to place it in the genus Acros- 

 ticlmm. 



Sp. H. spicata [Linib.) (v v.) ; H. platyrhynehos, J. Sm. ; 

 H. brachystaohys, /. Sra. {H. spicata var. hrachystaohys, 

 Hooh. Gard. Ferns) (v v.). 



H. spicata is found very generally throughout the tropics 

 of the Eastern Hemisphere, while II. plaiyrhynclws is as yet 

 only known as a native of Luzon. 



35. Leptochilus, Kaulf. (1824,). 

 Acrosticlmm sp. auct. ; Hook. Sp. Fil. 



Surculum casspitose, or slender elongating. Fronds 

 6 to 18 inches long, of two forms ; the sterile simple, 

 lobed, or pinnatifid, smooth ; the fertile contracted, linear- 

 rachiform, its margins revolute and indusasform. Primary 

 veins of sterile frond evident, straight or fiexuose, venules 

 compouudly anastomosing, lieceptaclcs eloBg&ted, oompital. 

 Sorus linear, continuous, uniserial, on each side of the 

 costa, ultimately confluent, destitute of scales. 



Type. Acrostiohum axillare, Cav. 



Illust. Hook. Gard. Ferns, t. 6 ; J. Sm. Ferns, Brit, and 

 For., fig. 20. 



Obs. — I have already stated that on account of the 

 contraction of the fronds in the preceding genera, the 

 individuality of the normal pnnctiform receptacle is des- 

 troyed, and they become so connected aa to form a continuoua 



