31 . 
THE PRICKLY-TOOTHED BUCKLER FERN. 
Lastrea spinulosa. 
Plate 11 , Fig. 1 , Page 331 . 
There is so much resemblance between this species and 
Lastrea cristata that the claim made to rank them as dis- 
tinct species has been disputed, several botanists considering 
the one merely as a variety of the other. Curiously enough 
in spite of the great rarity or rather of the extremely narrow 
range of Cristata as compared with Spinulosa the former 
has usually been considered — by those who regard the one 
as a variety of the other — as the normal, and the latter as the 
variety. The relative position, however, if this view of their 
relationship be accepted, should certainly be reversed, Spinu- 
losa being regarded as the normal form from the fact of its 
being much more abundant, and Cristata as the variety — 
for the instances which give rise to a rule should always be 
greater in number than the exceptions. Here, however, the 
two Ferns are regarded as distinct species, and the descrip- 
tion of the present species will consist chiefly of an indication 
of the points of difference between them. Both are found 
in precisely similar situations, namely, in the damp and 
marshy hollows of woods, and in bogs and boggy heaths. 
Description. — The rootstock of this Fern multiplies by 
extending into branches with numerous crowns, as in Cristata, 
and the fronds are of the same length, namely, from one to 
three feet. The pinnae also are set on the racliis, in very much 
