J. SMITH ON THE GENERA OF FERNS. 193 



fertile ; sori often conjiuent ; indusium smooth or pilose, some- 

 times cochleate. 



Examp. 1. L. semicordata, {Sto.) 2. L. atrata, {Wall.) 

 3. L. falciculata, (Radd.) 4. L. chrysoloba, (Link.) 5. 

 L. serra, (Sw.) 6. L. invisa, (Sw.) 7. L. appendiciilata, 

 ( fVall.) 8. L. multijuga, (fVall.) 9. L. Sprengelii, {Kaulf.) 

 10. L. patens, {Sw.) 11. L. polyphylla, (/:a«/^.) 12. L. 

 novaboracense, {Sw.) 13. L. Thelypteris. (Thelypteris 

 palustris, Schott.) 14. L. Oreopteris, {Sic.) 15. L. Filix- 

 nias, {Sxv.^ Dryopteris, Schott.) 16. L. elongata, {Sw.) 17. 

 L. patentissima, {Wall.) 18. L. marginale, {Siv.) 19. L. 

 venusta, {Hew.) 20. L. macrocarpa. (Arthobotrys, Wat//.) 

 21. L. Goldiana, (/7ooA. e< Grev.) 22. L. dilitata, (Sw.) 

 23. L. eriocarpa, ( fFa//. Hypodematium, Kunze.) 24. L. 

 ascendens, {Hew.) 



Illust. Hook, et Grev. Ic. Fil. t. 102. Schk. Crypt, t. 37, 38. 

 Hook. Gen. Fil. t. 45. A. 



Obs. This extensive genus presents nearly the same fea- 

 tures as regards habit and venation to that which now cha- 

 racterizes the genus Polypodiiim ; and, from my own observa- 

 tions, I am convinced that there are many species placed in 

 Polypodium^ which, if examined in an earlier state of growth, 

 would prove to be furnished with an indusium, and to belong 

 to this genus. In the numerous species of Lastrea, the in- 

 dusium varies in texture and form, being more or less mem- 

 braneous, plain or vaulted ; but in my view not affording suf- 

 ficient character for constituting genera, and like Polypodium, 

 the position of the sori also varies in being medial or termi- 

 nal ; but which also affords no determinate character, and as 

 the more or less regular pinnate or forked character of the 

 venation depends upon the ultimate lacinise or segments of 

 the frond being more or less entire or laciniated, it therefore 

 becomes difficult to arrange this numerous group of species 

 otherwise, than by the circumscription of the frond. 



In at least two species the fertile fronds are contracted and 

 densely occupied by the sori, which state forms the genus Artho- 

 botrys of Wallich ; but this state of the frond appears in a great 



Vol. IV._No. 28. 2 b 



