INTRODUCTION. XIU 



cristatum. The numerous species of Lophodium have hitherto 

 formed part of what might be called the retenue of Polypodium, 

 Polystichum, Aspidium, Nephrodium and Lastrea, but have 

 never, as I believe, constituted a genus : it is surprising that 

 the flat, notched involucre of this genus did not attract the 

 attention of those botanists who have treated of that organ as 

 being so important. The other genera are, I believe, generally 

 received. 



Without going back to Gerarde, Parkinson, and that ancient 

 school of herbalists, it will be sufiicient to begin a summary 

 of the species of British ferns with Eay's ' Synopsis.' In 

 this admirable work, no less than forty-eight species are enu- 

 merated. I omit twelve of them : — 1. Poljrpodium murale, 

 which, as the editor distinctly explains, is only a variety of 

 Polypodium vulgare, figured at p. 41. 2. Polypodium Cam- 

 brobritannicum, the well-known var. Cambricum of the same 

 plant, figured at p. 45. 3. Trichomanes foHis eleganter inci- 

 sis, is the variety of Asplenium Trichomanes figured at p. 352. 

 4. Filix aculeata major, is one of the forms of Polystichum 

 aculeatum, figured at p. 111. 5. FiUx Lonchitidi afiinis is re- 

 presented at figure b on the same page. 6. Filix pumila saxa- 

 tilis is the seedling plant of my Lastrea montana, p. 129. 7. 

 Adiantum, an album tenuifolium, which Dillenius considered a 

 variety of Euta-muraria. 8. Adiantum majus Coriandri, &c., 

 and 9. Adianto vero afiinis, both of which are forms of Asple- 

 nium mariuum. 10. Filix lobata, which is a leaf of Anemone 

 nemorosa. 11. Adiantum nigrum pinnulis Cicutariffi, which I 

 believe to be the divided and acute form of fragile, represented 

 in the left-hand figure at p. 87. And 12. Filix pumila petraea, 

 which I agree with the editor m supposiag a young plant of 



