PELLAEA ATROPURPUREA AND P. GLABELLA 81 
or very obscurely toothed, the teeth being visible only 
under a microscope of fairly high power. The scales of P. 
glabella usually have, on each side, a few rather prominent 
blunt teeth, easily seen with a good handlens. 
The spore measurements given by Pickett appear 
to be considerably too large, at least as applied to her- 
barium material. My measurements are as follows: 
Spores of P. atropurpurea, 50-68y. x 45-55u; spores of 
P. glabella, 55-85y, x 45-60u. Whether this discrep- 
ancy is due to the shrinking of the spores in herbarium 
material, or to an error in scale, can be determined only 
by examining fresh spores which are not available at 
the present writing. I find that, on the whole, the 
Shape of the spores does not differ materially in the two 
species. Both have some spores which are plainly 
tetrahedral, some obscurely tetrahedral, some nearly 
spherical and some elliptical. In both species the 
Spores have a wrinkled epispore, that of P. atropurpurea 
being much more coarsely wrinkled than that of P. 
glabella. In both species, in mounts of spores from 
herbarium material, the epispore is apt to crack off ex- 
posing the nearly smooth, pale yellow spore. 
In conclusion, it is well to note that there can be no 
Possible doubt as to the proper application of the two 
Specific names. In both cases the original descriptions 
are truly diagnostic. In addition, it is to be noted that 
Pteris atropurpurea of Linnaeus was founded on one of 
Clayion’s plants described by Gronovius and cited as 
stowing “‘ad ripam fluminis Rappahannock in umbroso 
loco ad Juniperi radicem juxta promontorium Anglice 
Point-look-out dictum,”’* a region where P. glabella is 
unknown. On the other hand, the habitat originally 
clied for P. glabella is “Kimmswick prope St. Louis. 
Visconsin, Columbia anglica (Lyall). Rocky Mis.,’* a 
Sige , 
, pronovius, J. F., Flora Virginica 197. 1739. 
Kuhn, Max, Reliquiae Mettenianae. Linnaea 36: 87. 1869. 
