PELLAEA ATROPURPUREA AND P. GLABELLA 83 
cleft into nearly equal segmenis, or, still more rarely, 
ternately compound. In the typical form of the species 
the lower one or two pairs of pinnae are nearly always 
ternately compound, even in depauperate individuals. 
The fertile pinnae of the variety are ovate or elliptical, 
and conspicuously broader than the ovate-lanceolate 
fertile pinnules of the common form. They also have 
less revolute margins, and are of a somewhat thinner 
texture. In all these respects, however, eastern speci- 
mens of this species display considerable variation, and 
occasionally approach very close to the western variety. 
Thus a specimen in the Gray Herbarium from Mar- 
garetia, Erie Co., Ohio, collected August 22, 1895, by 
E. L. Moseley, has some fronds which are almost exactly 
like those ordinarily seen in the variety occidentalis, 
though the spores and the scales are those of the typical 
eastern form. 
In Pellaea glabella var. occidentalis the cells of the 
scales are oblong, and even shorter than in the typical 
form of this species, being only 3-5 times as long as 
they are wide. The spores of the var. occidentalis 
differ from those of the typical form in being uniformly 
tetrahedral, 45-55u. in diameter. 
In view of the inconstancy of some of these points of 
difference, and the very minute character of the others, 
lt seems best to the author to regard this form as a 
8eographical variety of Pellaea glabeila. All specimens 
of it in the Gray Herbarium are from South Dakota and 
Wyoming, though it probably has a somewhat more 
extended range. It is to be noted, however, that many 
Plants which have been distributed or cited under the 
names P. pumila Rydb., and P. occidentalis (E. Nelson) 
Rydb., have been incorrectly identified, and belong 
either to the following variety, or to P. Breweri. 
The following is a list of the specimens of P. glabella 
var. occidentalis in the Gray Herbarium: 
