FERN TRIPS IN VIRGINIA 111 
ASPLENIUM ANGUSTIFOLIUM. One good sized clump — 
was observed. 
ASPLENIUM FILIX-FORMINA. Less abundant in this 
locality than one might expect. 
CAMPTOSORUS RHIZOPHYLLUs. Carpets the ground 
and rocks in every direction. 
POLYSTICHUM ACROSTICHOIDES. Common. 
DRYOPTERIS MARGINALIS. Common. 
FILIX BULBIFERA. In great profusion. 
Firx FrAGILIS. Not nearly as common as F. bulbifera. 
Woopsia ostusa. Fairly common. 
BoTRYCHIUM TERNATUM. Common 
BoTRYCHIUM TERNATUM, var. DISSECTUM. Common. 
BoTRYCHIUM VIRGINIANUM. Common 
Specimens of A. Bradley’, A. montanum, A. Ruta- 
muraria, A. resiliens, A. ebenoides, and Hanes 
spinculose: var. dilatata, were submitted to Dr. Cam 
bell E. Waters, for his confirmation of our one a 
tion, in order that there might be no question as to the 
correctness of our list. 
The foregoing is practically nothing more than a sort 
of check list of the ferns to be found in these two local- 
ities. However, these places are not very far apart, 
are located in the same range of mountains, and pre- 
sumably have the same climate. It is, therefore, of 
more than passing interest to note that ferns which 
are common in one place are either missing in the 
other or, if found at all, in exceedingly small quantities. 
Since the climate is essentially the same, it is obviously 
a matter of soil which causes these differences, and a 
brief discussion of this phase of the situation may prove 
of value. 
The Natural Bridge consists of dolomitic limestone, 
the limestone formation extending for some distance 
around the Bridge. About a mile or more to the West, 
there is a small outcrop of sandstone. At Rock Enon, 
