GENERA OF FERNS. 651 
the presumed obliquity of the ring in Cyathee takes place 
merely by mechanical pressure, each sporangium being inclined 
upwards, sessile, and compactly seated round an elevated 
receptacle ; therefore the pressure upon each other causes the 
lower part to become flattened and attenuated, especially on 
the inner side, which readily accounts for the not truly verti- 
cal direction of the ring. 
'The general habit of Cyathee may be viewed as analogous 
to those species of Polypodium and Lastrea, that have large 
decompound fronds; and as this tribe contains genera with 
naked sori, and also genera having indusia analogous to seve- 
ral genera of Aspidiee, the arboreous habit and the elevated 
receptacle must be considered as the only technical charac- 
ters that distinguish Cyathee from Polypodiee and Aspidiee. 
119. Scnizocana, J. Sm. 
(Cyathez sp., R. Br., Wall., Hook. et Presl.) 
Veins pinnately-forked ; venules direct, free; sori medial. 
Indusium globose, calyciform, opening in 4-6, nearly equal, 
spreading laciniæ. Receptacle globose. 
Fronds smooth, linear-lanceolate, or pinnate, rarely bipin- 
nale, margin of segments entire. Sori produced in 2 or 3, 
nearly regular, transverse rows. l bm 
Examp. |. S. sinuata (Hook. et Grev.) 2. S. Brunonis 
(Wall) 3. S. levigata (Willd.) 
Ilust. Hook. et Bauer gen. fil. t. 2. Hook. et Grev. ic. fil. 
t. 106. 
Obs. Mr. Brown, in the Prodromus Flore Nove Hollandie, 
p- 158, observes that, besides the genuine species of Cyathee 
where the sori are seated on the division of the veins, 
there are species from the Moluccas, in which the sori are 
produced on the middle of the veins; which character, to- 
gether with the very distinct habit of that species and its 
allies, has induced me to constitute of them the present 
genus. I regret not having seen specimens of Cyathea ma- 
rattioides of Willdenow ; that species, according to Presl, 
