Fink: THE LICHENS OF MINNESOTA. 725 



107. Yerrucaria nigre«cens Pers. 



On calcareous and granitic rocks, common. June 25, 189b, 

 no. 25; June 28, 1896, no. 42; July 2, 1896, no. 67. 

 Not previously reported from Minnesota. 



108. Yerrucaria fuscella Fr. 



On calcareous rocks, rare. July 8, 1896, no. 124; July 18, 

 1896, no. 184. 

 Not previously reported from Minnesota. 



109. Yerrucaria muralis Ach. 



On calcareous rocks, rare. June 28, 1896, no. 36; July 9, 

 1896, no. 125. 

 Not previously reported from Minnesota. 



110. Pyrenula punctiformis (Ach.) N^eg. 



On trees, infrequent. June 17, 1896, no. 35; July 16, 1896, 

 no. 188. 



Two forms are placed here, one having 2-celled spores and 

 the other 4-celled ones. Doubtless one will eventually be 

 placed elsewhere. 



Not previously reported from Minnesota. 



111. Pyrenula leucoplaca (Wallr.) Kbr. 



On trees, probably rare. July 4, 1896, no. 87; July 11, 1896, 

 no 153a. 



Not previously reported from Minnesota. 



112 Pyrenula nitida Ach. 



On trees, infrequent. July 4, 1896, no. 99. 

 Not previously reported from Minnesota. 



113 Pyrenula thelena Ach. 



On Betula, rare. July 4, 1896, no. 97. 

 Not previously reported from Minnesota. 



