J. SMITH ON THE GENERA OF FERNS. 49 



Species. 1. A. crispus. Bernh. 2. A. acrostichoides, Spreng. 

 3. A. Brunonianus (Cryptogramraa. Wall?) 4. A. gracilis. 

 J. Sm. (Cheilanthes. Kaulf.) 5. A. ciliatus. Presl. 6. A. 

 hirsutus. Presl. — lUust. Schk. Crypt, t. Hook, et Grev. Ic. 

 Fil. t. 29, 158. 



Ohs. From the circumstance of the species of this genus 

 having the margin of their fronds membranaceous and indusii- 

 form, and also by the sori being confluent, forming as it were 

 a transverse marginal sorus ; they have, on that account, been 

 placed in, or near to Pteris ; but as the indusliform margin 

 is formed by the changed state of the fertile frond, and does 

 not rise from a sporangiferous receptacle as in true Ptendeoe; 

 I consider therefore Allosorus to be more naturally placed 

 near Poh/podium, from which it differs more by the contracted 

 character of the fertile fronds, than in the position or form of 

 the sori. 



8. Jamesonia, Hook. €rrev. 



(Pteridis sp. Sw. Allosori sp. Presl.) 



Veins radiating, free. Sporangia medial. Sori round, 

 crinite, 3 to 5 confluent, forming one central, compound, round 

 sorus (to each pinne), the margin of which is revolute and 

 conniving, forming a universal iudusium. — Fronds linear from 

 6 to 12 inches high, pinnate. Rachis thickly covered with 

 long articidated hairs, pinnae reniform, cordate, imbricate, 

 concave. 



Species. J. imbricata, Hook, et Grev. 



Bauer s illnsf. gen. fil. t. 13. Hook. Grev. ic. fil. t. 178. 



Obs. This genus is founded upon a solitary species, which 

 on account of the pinnae having an indusiiform margin, has 

 led it to be considei'ed as a species of Pteris ; but, as in the 

 preceding genus, the position of the sporangia and free veins 

 show it to belong to Polypodiece. In the character and figure 

 given in the Icones filicnm, it is made to appear as having 

 only one sorus, but on examination it appears that there are 

 usually five sporangiferous points, which, by being produced 

 very close to each other soon become confluent, and then 

 appear like one sorus. 



Vol. IV.— No. 25. G 



