108 TTERIS. 



8. — Onychium, one species. 



Fee, in his "Genera Filicum": — 



1. — Ptcris, a large family. 



2. — Pcllcra, an extensive family. 



3. — Phorolobus, three species, including Cryptogramma. 



4. — Onychium, nine species. 



5. — Doryoptcris, seven species. 



6. — Litobrochia, a large family. 



7. — Hctcrophlcbium, one species. 



8. — Amphiblcstra, one species. 



9. — Lonchitis, nine species. 



In the present work Platyloma has been separated from 

 Ptcris, hut the division Pcllcua has been retained as a 

 section of Platyloma, rather than devoting a genus to it. 

 Doryoptcris and Onychium are also treated each as a distinct 

 genus; whilst Litobrochia, Lonchitis, and Camptcria, are placed 

 as sections of Ptcris. 



There is a solitary representative of this extensive family 

 in Great Britain, viz. — Ptcris aquilina, and, strange to say, this 

 species has a very great geographic range, although bearing a 

 different name in several countries. Mr. Moore mentions the 

 following as species not to be distinguished from our Ptcris 

 aquilina: — 



P. lanuginosa, Bory. Ceylon, Mauritius, and Abyssinia. 



P. decomposita, Presl. Sandwich Islands. 



P. ca u data, Linna?us. North America and Jamaica. 



P. rccurrata, Wallich. Nepal. 



P. arachnoidca, Kaulfuss. Rio de Janeiro, Brazil, Trinidad. 



P. csculcnta, Forster. New Holland. 



The name Ptcris is derived from Ptcron — a wing, in 

 reference to the form of the branching of the fronds of this 

 genus. Mr. Moore remarks that originally the family of 

 Ptcris embraced nearly two hundred species, but from subdi- 

 visions and by the recognition of the same species under two 

 or more names the number has been greatly reduced. 



Mostly the species arc tall coarse-growing Ferns, very easily 

 cultivated; the length of fronds varying from one to ten feet. 

 They are pinnate, bipinnatifid, or decompound, glabrous or 

 pilose. Veins forked, the venules being direct, and having the 

 apices connected together by a sporangiferous receptacle. 



