Classification and Nomenclature. 51 



102. Classification of Order Filices. The subdivisions of 

 thie order Filices have been various, and the following are given 

 for comparison with that followed by the leading American sys- 

 tematists. As the Synopsis Filicum, from which the second is 

 taken, is largely used in this country, the American genera are 

 distributed under their respective tribes. 



103. Mettenius' Arrangement. 



Sub-Order I. Hymenophyllace^. Ring complete, 

 oblique or transverse. 



Sub-Order II. Gleicheniace^. Ring complete, trans- 

 verse. 



Sub-Order III. Schiz^eace^. Ring complete, apical. 



Sub-Order IV. OsmundacE/E. Ring rudimentary or 

 none. 



Sub-Order V. Marattiace^.* 



Sub-Order VI. Cyatheace^. Ring complete, oblique. 



Sub-Order VII. Polypodiace^. Ring complete, verti- 

 cal ; including the five tribes : Acros- 

 lichecE, PolypodiecE, Aspleniecs, Aspi- 

 die^ and Davalliees. 



104. Hooker's Arrangement. 



Sub-Order I. Gleichemace^e. (2 genera.) 

 Sub-Order II. Polypodiace«. (61 genera.) 

 Tribe i. Cyathe^. (6 genera.) 

 Tribe 2. DicKSo.viEyE. (6 genera— 0«oc/«.z, Wood- 



sia, Dicksonia.) 

 Tribe 3. Hymenophylle.^. (3 genera — Tricho- 



manes. ) 

 Tribe 4. Davallie.«. (2 genera — Cystopteris.) 

 Tribe 5. LiNdsaye^. (2 genera.) 

 Tribe 6' Pteridete. (13 genera — Adianium, Cheil- 

 anthes, Cryptogramme, Pellisa, Pteris, Cera- 

 topteris, LomaiHa.) 

 Tribe 7. Blechne^. (4 genera — Blechnum, Wood- 

 war dia. ) 

 Tribes. Asplenie^. (^ gftntra.— Asplenium.) 

 Tribe 9. Scolopendrie^e. (i genus — Scolopen- 



drium, including Camptosorus.) 

 Tribe 10. Aspidie/E. (6 genera — Aspidiuml, Ne- 

 phrodiumX, Nephrolepis* 



'■' Not recognized by Mettenius as a diatinct order. 

 ^United under Aspidium by American botanists. 



