prevailing rock is limestone. Geological formations 

 have an important bearing on the distribution of ferns 

 and we have enough of the basalt and limestone to fur- 

 nish homes for a number of species that prefer such a 

 habitat. 



The more interesting parts of the state have been 

 very thoroughly botanized for many years, but in spite 

 of this fact several of the rarer species listed are of 

 recent discovery. It has not been thought desirable to 

 increase the number of species and varieties by listing 

 all the slight variations or abnormal forms that have 

 at some time been described. Only those varieties 

 seeming to have in this region well marked and perma- 

 nent characteristics are given a place in the list. Fur- 

 ther study may show that some of these excluded forms 

 are good varieties and give them a place in future pub- 

 lications. The nomenclature used is. in accordance with 

 the new Vienna code adopted by the Vienna Congress 

 of 1905. 



POLYPODIA CE^E. 



Poly podium vulgare L. Common Polypody. 

 Frequent throughout on shaded ledges. The form 

 known as var. Cambricum with broader pinnae and cut 

 segments sometimes occurs. 



Phegopteris polypodioidcs Fee. Long Beech-fern. 

 In rich moist woods and on shaded banks ; rare or local 

 in eastern and southern districts, becoming common to 

 the northwest. 



Phegopteris hexagonoptcra Fee. Broad Beech- 

 fern. Frequent of occasional in rich woods, either 

 moist or dry, throughout. Some forms approach P. 

 polypodioidcs Fee. in appearance. 



Phegopteris Dryopteris Fee. Oak Fern. Rocky 

 woods in rich moist soil. Rare or local over most of 

 the state, becoming frequent to the northwest. 



Adiantum pedatum L., Maidenhair. In rich woods 

 frequent throughout. 



