236 



HYMENOPHYLLACEAE 



[CH. 



but peculiar scales are found in some species of TricJiomanes: for instance 

 T. mevibranaceum bears convoluted marginal scales which replace the stififly 

 branched hairs of other species (Fig. 504, E). 



Fig. 505. Habit o{ Hymcnophyllum. A, Hym. cruentum Cav. B, Hytn. dilatalwn Sw. 

 C, Hy»i. aitstrale Willd. (After Sadebeck, from Engler and Prantl.) 



The leaves are very commonly of the Sphenoptej'is-X.ypQ, each narrow 

 segment having a single vein (Figs. 505, B, C, 504, C). But various degrees 

 of webbing may be seen, and in extreme cases the blade may appear entire 

 both in Hymeiiophylbnn (Fig. 505, A), and in TricJiomaties (Fig. 504, /i, B). 



