344 CHARACTERS OF TRIBES AND GENERA. 



more ideal than actual. But, for the sake of convenience, 

 I admit the necessity of following the usual practice of 

 authors, and consequently adopt the genera as heretofore. 



In at least two species the fertile fronds are contracted 

 into a linear entire or racemose rachiform spike, and upon 

 this character Bory founded two genera, Hymenostachys 

 and Feea. The first of these has the peculiarity of being 

 the only species of Hymenopliyllece having anastomose 

 veins ; and that circumstance, in conjunction with the 

 contracted form of the fertile frond, induced me in 1841 to 

 adopt it as a distinct genus, which I still continue to do. 

 In Feea the venation is free, and it consequently differs 

 from Trichomanes only by the contraction of its fertile 

 trond, so that I did not at the same period regard it as 

 distinct ; but upon reconsidering the subject, I see no 

 reason why Feea should not have as good a right as 

 Lomaria to be considered a distinct genus, it having the 

 same relationship with Trichomanes that Lomaria has with 

 Blechnum. 



In the preceding observations I have mentioned the 

 chief points of structure employed by authors for classi- 

 fying the species ; and, although I have given the subject 

 much consideration, I can find no other tangible characters 

 whereby the number of genera may be advantageously 

 increased. This is, however, different from the view taken 

 by Presl, who arranges the whole under no less than 

 twenty-three genera, as stated at page 30. A critical 

 review of these so-called genera would occupy more space 

 than can be afforded in the present work, and would serve 

 no practical purpose. The characters of his new genera 

 appear to me to be in many cases imaginary or derived 

 from imperfect materials, the same species being in some 

 cases placed under separate genera. 



