68 AMERICAN FERN JOURNAL 
all the species found are common in northern Europe and 
North America. Further, it is difficult to point out 
differences between the arctic forms of a species and 
those of the temperate regions. Some of them (especi- 
ally the Equiseta and Lycopodia) are represented by low, _ 
appressed forms, which, however, may be found also in- : 
mountains of the temperate zone. No species may be. 3 
said to be especially accommodated to arctic climate; 
Dryopteris fragrans and species of Woodsia might seem 
to be so by their dense covering of scales, but it is better 
to say that they are accommodated to the alpine climate © 
of the higher mountains of the temperate regions and, 
therefore, possess the power of enduring the extreme 
climate of the farthest north. 
A study of the arctic ferns will throw light upon ; 
several difficult problems with regard to the relationship — 
between the American and the European flora. I shall, 
however, not discuss these questions here but sagen 
make them the subject of a later paper. 
In the following list all species of Pteridophyta known 
as arctic are enumerated; the figure added to each spe- 
cies means the degree of latitude of the northernmost 
locality i in which the species was found. 
1. Woodsia alpina (Bolton) Gray. Hayes Sound, 4 
_ 53’; East and West Greenland, about 74°; Baffin Land. 
——-Q.-W. ilvensis (L.) R. Br. Baffin Land; W. Greenland, 
72° 48’; E. Greenland, 70°; Chukches Land. 
2: W. glabella R. Br. Baffin Land; W. Greenland, 74° 
18’; Hayes Sound, about 79°; E. Greenland, about 77” 
4, Cystopteris fragilis (L.) Bernh. Perhaps the most 
common arctie fern, found throughout, where ferns ¢ 
a — 43’ mal = in 1 E. ov to 
