70 
FERNS : BRITISH AND FOREIGN. 
through Phylloglossum Drummondii, a singular little 
plant, having the appearance of a small plant of Ophio- 
glossum Lusitanicum, but with a spike formed of small 
bracts containing sporangia in their axis, analogous to 
Lycopodiacece ; otherwise the family of Lycojpods stands 
quite isolated, appearing to have no very evident 
transition forms connecting it with any other except 
the extinct order Lepidodendrece : the same may be 
said of the last order, Marsileacece. 
The most important of the above orders is F 'dices. 
Sir W. J. Hooker, in the “ Species Filmum,” describes 
two thousand five hundred species of annulate Ferns, 
which, with those described since the first publica- 
tion of that work, twenty years ago, may now be 
considered to amount to no fewer than three thou- 
sand. To arrange and classify this mass of species is 
no easy task. The chief writers on Ferns adopt the 
difference in the position and direction of the ring, as 
the first important character for subdividing the order. 
This, however, divides it very unequally, the greater 
mass having the ring of the spore-case vertical, which ’ 
characterizes the sub-order Polypodiacece ; this I have 
in the following arrangement subdivided into eleven 
tribes, as follows : — 
Conspectus of Arrangement of Orders, Sub-Orders, 
and Tribes. 
1. Annulatae . — Sporangia furnished with an articulate elastic ring. 
Order I. — Filices. 
Frond circinately unfolding. Sporangia furnished with vertical, 
horizontal, or sub-oblique ring. 
Sub-Order I. — Polypodiacece. 
Ping vertical. 
