J. SMITH ON THE GENERA OF FERNS. 185 



contracted, only the lower venules anastomose, the sori- 

 ferous venules of the narrow laciniae being free. Presl ap- 

 pears to have seen only the fertile state, and that without the 

 indusium, which has, I apprehend, been the cause of his plac- 

 ing it in Polypodie(E. 



82. Onoclea, Linn. 



Veins (of sterile fronds) reticulate, fertile frond contracted, 

 segments bacciform, constituting a universal indusium; fertile 

 iJem/7es direct, free; sporangia medial, their pedicels concrete; 

 sori round, 4 — 6 confluent; special indusium lateral, cucul- 

 late, very membraneous. 



Fronds of tivo forms, the sterile pinnate ; pinnce sinuous or 

 pinnatifid; fertile frond hipinnate; pinmiles contracted, ses- 

 sile, their margin membraneous, conniving, forming a unila- 

 teral raceme of globous hacciforni segments, each compactly 

 filled with the sporangia of confluent sori. 



Species. O. sensibilis, i««n. Illust. Schk. crypt, t. 102, 103. 

 Hook. Ge7i. Fit. t. 82. 



Obs. On first viewing this singular but well-known fern, 

 it may seem strange why it should now be placed in Aspi- 

 diees, having been hitherto placed in affinity with Blechniim 

 and Woodwardia, which has no doubt arisen by the membra- 

 neous conniving margin of the fertile segments haying been 

 considered as a true indusium, and from authors not having 

 paid due regard to the apparent membraneous scales which 

 are found interposed between the confluent sori, which mem- 

 brane I find is cucullate, and attached on the sporangiferous 

 receptacle analogous to the interiorly attached lateral indusia 

 of many Aspidie^e. What further strengthens my opinion 

 that Onoclea should be placed in Aspidiece is, that the habit 

 and venation of the sterile fronds are similar to the genus 

 Sagenia, the fertile fronds of some species of that genus being 

 somewhat contracted, and indeed only wanting a little more 

 contraction to pass into Onoclea. Thus Onoclea presents the 

 same affinity with Aspidium that Stndhiopteris does with Poly- 

 podium. 



Vol. IV No. 28. 2 A 



