ON THE VARIETIES OF BRITISH FERNS, ETC. 
285 
are but separated into a few capillary divisions, while in the other they are so 
numerous as to resemble a bunch of hairs. 
Cistopteris dentata. 
C. dentata, Brit. Flo . (Hook.), 3rd Ed., p. 451; 4th Ed., p. 386. 
44 44 Brit. Ferns and Allies (Francis), p. 21, pi. 1, figs. 9, 10* 
Folypodium fragile, Fil. Bril. (Bolt.), p. 50, tab. 27. 
Cystea-dentata, Brit. Bot ., With. (MacGilliv.), p. 382. 
The variety /3 angustata , if it has any right to the title, differs considerably in 
appearance from the var. <*. My specimens strictly resemble those mentioned by 
Hooker (Brit. Flo.), and have the frond broader, and the pinnules rather more 
divided. But I think further observation is necessary to decide how far it is 
distinct. 
(3 somewhat approaches C. fragilis, from which it is easily known by the 
broader frond and more obtuse pinnules, which are also less divided. In fragilis 
also the rachis is dark and polished, which is not the case in my specimens of 
dentata. 
C. Alpina is well distinguished from either by its small, tripinnate frond, which 
is also somewhat broader than in C. fragilis. 
Aspidium lobatum. 
A. lobatum, Brit. Flo. (Hook.), 3rd Ed., p. 449 ; 4th Ed., p. 384. 
44 44 Brit. Ferns and Allies (Francts), p. 26, pi. 2, fig. 2. 
44 44 With. Brit.Bot. (MacGilliv.), p. 381. 
Polipodium aculeatum, Fil. Brit. (Bolt.), p. 48, tab. 26. 
j3 (lonchitidoides). This variety is formed by the union of the pinnules form¬ 
ing a pinnate frond; in this state it can only be mistaken for A. lonchitis, in 
which the fronds are pinnate, the pinnse falcate, ciliato-serrate, acutely and 
distinctly auricled on the upper base. 
In lonchitidoides the union of the pinnules is seldom complete, the lower pinnae 
being often either pinnate or pinnatifid, and in the state most differing from the 
common plant; they are more or less divided, and the lobes serrate; the frond is 
also larger, and generally occurs about intermediate between lonchitis and lobatum. 
Very young fronds of the latter take the characters of lonchitidoides. 
Sir W. J. Hooker still (4th Edit.) retains his opinion that A. lobatum, aculea¬ 
tum, and angulare must either constitute one or three species. I am little qualified 
to give an opinion on this point, my opportunities of observing having been far 
from as numerous as I could desire. But I have always hitherto readily known 
lobatum by its more rigid texture, and the larger size of the pinnules generally, 
but more particularly the upper primary one, which, however, is but serrated like 
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