32 



HEERE 



department of the University of California, I am indebted for the loan 

 of literature otherwise inaccessible. 



My sincere thanks are due Prof. William Russell Dudley, head of the 

 department of systematic botany at Leland Stanford Junior Univer- 

 sity, for timely assistance and helpful criticism in many ways, espec- 

 ially in the final preparation of this paper. To him I dedicate this 

 work, as long since he called my attention to the distinctiveness of the 

 Santa Cruz Peninsula as a biological region. 



Los Gatos, California, October, 1908. 



ARTIFICIAL KEY TO GENERA OF LICHENS OF THE SANTA CRUZ PENIN- 

 SULA, CALIFORNIA. 



Crustaceous Lichens. 



A. Thallus absent. 



B. On thallus of Pertusaria; apothecia top-shaped. 



IX. Sphinctrina 

 BB. On rock, wood, or bark. 



C. Asci multisporous, spores minute XXVI. Biatorella 



CC. Spores not more than 8. 



D. Apothecia lecideine XIX. Lecidea 



DD. Apothecia lecanorine XLIII. Lecanora 



AA. Thallus more or less developed. 



E. Apothecia pyrenocarpous, more or less globose, immersed, hemi- 

 spherical or sessile, with a terminal pore. 

 F. Algae Trentepohlia. 



G. Paraphyses branched and twining IV. Arthopyrenia 



GG. Paraphyses simple and free V. Porina 



FF. Algae Pleurococcus. 



H. Thallusuniformcrustaceous; spores 8, simple... T. Verrucaria 

 HH. Thallus of sub-foliaceous to minute squamules. 



/. Spores 8, simple, colorless II. Dermatocarpon 



II. Spores 2, muriform, yellowish to brown. .III. Endocarpon 

 EE. Apothecia not pyrenocarpous. 



J. Apothecia more or less stalked, or sessile, spores extruded and 

 forming a sporal mass or mazaedium covering the disk. 



K. Apothecia containing algae IX. Sphinctrina 



KK. Apothecia not containing algae. 

 L. Apothecia on long stalks. 

 M. Thallus and stipe greenish-yellow, powdery. 



VII. Coniocybe 

 MM. Thallus and stipe not yellow. 



N. Spores bilocular VI. Caliciiim 



NN. Spores 4-8 celled VIII. Stenocybe 



LL. Apothecia short-stipitate or sessile. 



