298 CRYPTOGAMIA— FILICES. Cystea. 



leaves them naked, more prominent, sometimes crowded 

 or confluent. Capsules brown or black. 



In reviewing the whole order of Ferns, for the purpose of 

 establishing their generic distinctions on better principles 

 than had heretofore been suggested, I found the curious 

 little family, which I am now about to describe, so dis- 

 tinct in habit and characters from Polypodium, to which 

 it had been referred, as well as from what is now termed 

 Aspidium, that I could not associate it with either. The 

 globular shape of its irivolucfum, or cover, added. to the 

 insertion of that part underneath the capsules, its texture, 



■ and other circumstances, led rae rather to comprehend 

 these plants in the new genus Cyathea. This measure 

 has not been approved ; and the universal opinion being 

 against me, I so far submit. I cannot however agree 

 with those, whether competent to form an opinion or not, 

 who have referred them to Asjndium, and I pi'efer the 

 adoption of Prof. Bernhardi's genus Cystopteris ; only 

 retrenching the name as compounded of another esta- 

 blished one, Pteris. Neither the genus nor its name 

 having ever been received, such a necessary correction 

 can cause no inconvenience. I wish the character given 

 by this learned writer, and exhibited in his figure, were 

 liable to no more exception ; but even his original spe- 

 cies, C fragilis, has by no means constantly a bladder- 

 like, ovate, pointed cover, split along one side, as he 

 represents it. That part, though always at first wrapped 

 about each mass of capsules, is, generally, but moderately 

 concave ; being soon turned aside, and, in a more ad- 

 vanced state, variously jagged. It has no central or pel- 

 tate mode of attachment, nor any transverse fissure, 

 which characters belong to Aspidium. 



1. Q. fragilis. Brittle Bladder-fern. 



Frond oblong-lanceolate, doubly pinnate; leaflets ovate, 

 acute, pinnatifid, cut or serrated. Midribs bordered. 

 Masses crowded. Cover irregularly torn. 



Polypodium fragile. Linn. Sp. PI. 1553. Huds. 459. Bolt.Fil. 50. 



t. 27 and 46. Fl. Dan. i. 401. Hoffm. in Ram. and Ust. Mag. 

 fasc. 9. 1 1./. 14, a, b, c. Germ. u. 2. 9 j excl. the reference to 



Dickson. Ehrh. Crypt. 151. Dicks. Dr. PL 15. 

 P. polymorphum D, fragile. Villars Dauph. v. 3. 847. t. 53./. 

 P. album. Lam. Frang. v. 1. 21. 

 P. n. 1707. flail. Hist. v. 3. 15 ; excl. the reference to Vaillanl. 



