GENERA or FEKNS AND THEIR CLASSIFICATION. 7] 



Division I. — Eremohryd. 

 Fronds articulated with the rhizome. 

 Tribe I. Oleandrefe. — ySori round, medial, intra -marginal. 



.sram lateral, interiorly attached, or sometimes central 



plane. 



II. DavaUesB. — Sori round, terminal, marginal. Indusiuni 

 lateral, interiorly attached, vertically urceolate. 



IIL Polypodese. — Sori round or linear, naked. 



Division 11.^ — Desmohrya. 



Fronds adherent to the stem. 



Tribe IV. Acrosticheee. — Sori amorphous, naked. 



V. Grammitese. — Sori oblong or linear, simple, forked, or 

 reticulated, naked. 



VI. Phegopteridese. -.-Sori round, rarely linear, naked or 

 indusiate. Indusium lateral, interiorly attached or 

 central, or rarely calycifona. 



VII. Pteridese. — Sori marginal, round, or linear and trans- 

 verse. Indusiiim lateral, exteriorly attached on the 

 margin. 



VIII. Blechneae. — Sori intra-marginal, linear, transverse. 

 Indusium, lateral, exteriorly attached. 

 IX. Aspleneae. — Sori linear, oblique. Indusium lateral. 



X. Dicksoneae. — Sori marginal, round, or linear and 

 transverse. Indusium, lateral, interiorly attached, 

 conniving with the changed margin, forming a groove 

 or urceolate sub-bivalved cyst. 



XI. Cyathese. — Sori round, intra-raarginal. Ruccptachs 

 elevated. — Indusivm calyciform, or lateral and inte- 

 riorly attached or absent. " 



Sub-Order 11. — Gldcheniacete. 

 Ring horizontal {Sori intra-marginal.) 



Sub-Order III. — TJym.eno'phyllg.ceiv. 

 Ring horizontal or oblique. {Sori niarginal.) 



