J. SMITH ON THE GENERA OF FEUNS. 153 



chis; fertile contracted, bearing the sporangia in the form of a 

 broad transverse sorus. 



Species. L. pteroides, J. Sm. 



Ilhist. Hook. Gen. Fil. ined. 



Obs. This genus is founded upon a solitary species from 

 the island of Luzon, which in habit has some affinity with 

 Stenochlcena, but it is distinguished from that genus by its 

 reticulated venation, which is similar to that of Acrosfichunif 

 especially to one or two of the simple-fronded species; but 

 from which it differs not only in habit and in the articulated 

 petioles, but also in the sporangia, occupying only the mar- 

 ginal portion of the disk of the pinnte, therefore in that re- 

 spect having some similarity to Lomaria, and in its reticu- 

 lated veins to Litobrochia, but these two genera are charac- 

 terized with a special exteriorly attached indusium, and 

 consequently not belonging to this tribe. Probably this fern 

 may be the Leptochilus lomarioides of Blume, but his descrip- 

 tion is too brief to enable me to determine with certainty. 



45. Platycerium, Desv. 



Veins repeatedly forked, and distantly anostomosing ; ven- 

 ules internal, compoundly reticulated, with variously directed 

 free veinlets, terminating in the areoles, sporangiferous re- 

 ceptacle formed of an accessary layer of parallel anastomosing 

 veinlets which cross the sterile ones, producing crowded 

 linear lines of sporangia, and densely furnished with stellated 

 scales. 



Fronds thick and spongy. Sterile sessile, rounded, or eloyi- 

 gated, depressed, or ascending, permanent and successively im- 

 bricated, forming an elevated spongy mass. Fertile widening 

 upwards, and dividing into broad forked segments, producing 

 the sporangia towards the extremities, or on a special lateral 

 thickened lobe ; the whole {especially when young,) densely cover- 

 ed with stellated scales. 



Species. 1. P. alcicane, Desv. 2. P. stemaria, Desv. 3. 

 P. biforme, Bbime. 4-. P. grande, A. Cunn. 



Illust. Blume, Fl. Jav. t. 18. Hook. Gen. Fil. t. 80. B. 



Vol. IV No. 27. u 



