OF WESTERN PENNSYLVANIA. 47 



capsule oval, opening usually by four perpendicular slits along 

 the sides but remaining united at apex and base; columella 

 persistent; spores smoothish, mature in late spring. 



Cosmopolitan in mountainous or hilly regions on non- 

 calcareous exposed or dry rocks. In North America from the 

 Arctic regions south to northern United States. Occurs in" 

 riortheastern Pennsylvania and in northern West Virginia. 



