THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 31 



while the apotheci'a of others are covered with minute parasitic 

 apothecia. For example, the thallus of Heppia guepini is commonly 

 the host of a parasitic Endococcus. As Heppia is very often sterile 

 and the apothecia are not visible to the naked eye, one is exceedingly 

 apt to be confused by the Endococcus spores unless very careful sec- 

 tions are made. 



Nylander, Tuckerman, and others, described the minute apothecia 

 covering the disk of the fruit of many lichens as parasitic Buellias, 

 Lecideas, and the like. But as they never contain algae, and have 

 no thallus of their own, they are undoubtedly parasitic fungi, and 

 accordingly are not considered in the present work. 



In the preparation of this paper the author has been assisted at all 

 times, and especially in the study of the Lecideaceae, by his fellow 

 worker, Dr. H. E. Hasse, of Sawtelle, California, who has given his 

 time and energy wi hout stint. 



To my friend and teacher, Dr. Alexander Zahlbruckner, curator 

 of the botanical section of the Imperial Natural History Museum of 

 Vienna, Austria, I wish to express my gratitude for help while study- 

 ing in the Museum and collecting with him in the Styrian Alps. His 

 masterly treatment of lichens in Engler and Prantl's Die Naturlichen 

 Pflanzenfamilien has been followed in this paper. 



To Dr". W. G. Farlow of Harvard University I am indebted for 

 many favors and the gift of valuable specimens, while to him and Mr. 

 A. B. Seymour I owe the privilege of examining the Tuckerman 

 Herbarium. 



To the authorities of the British Museum and Kew Garden I am 

 indebted for courtesies while examining the herbaria there. 



The veteran Californian botanist, Volney Rattan, long time pro- 

 fessor in the San Jose State Normal School, generously gave me a 

 considerable collection of Californian lichens, presented him by H. N. 

 Bolander; this collection has been of great service in deciding many 

 difficult points. 



Prof. Bruce Fink, of Miami University, Oxford, Ohio, has kindly 

 determined a set of my collections of Cladonias, a labor of love which 

 I greatly appreciate. 



To Dr. William Trelease, the U. S. National Museum and the 

 Bureau of Plant Industry, at Washington, D. C., and to the Botanical 



