TABLE OE BRITISH FEENS. 



FEKNS in Latin FILICES are flowerless plants, 

 bearing seed-vessels (spore-cases) on their fronds. "All 

 Ferns" says Moore, "are referrible to one of three 

 groups : Ophioglossaeete Polypodiacece Marattiacece. 

 Of these the Ophioglossaceae and Marattiaceae are 

 but small groups, while the Polypodiacea: include the 

 greater portion of all known Ferns. These three 

 groups may each be regarded as a distinct order of 

 plants, forming together the Filices, or Ferns." The 

 Marattiacese are not found in the British Isles. We 

 have therefore only to do with the two natural orders 

 POLYPODIACEA! or True Ferns and OPHIOGLOSSACE.S: 

 or Adder's Tongue Ferns. 



POLYPODIACEJE are Ferns whose young fronds are 

 rolled up in a circinate form, and whose spore-cases 

 arc girt with an elastic ring. The presence of this 

 ring, in some form or other, nearly or completely sur- 

 rounding the spore-case, is the distinguishing pecu- 

 liarity of the True Ferns. Polypodiacese are divided 

 into those whose spore-cases are without valves and 

 those which are two-valved. In the first division 

 are two tribes or groups : Polypodinece, without 



