32 HERRE 



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 Gruz Peninsula as a biological region. 



Los Gatos, California, October, 1908. 



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

 SULA, CALIFORNIA. 



Crustaceans 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. 



DS 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. Thallus uniform crustaceous; spores 8, simple.. . . I. Verrucaria 

 EH. Thallus of sub-foliaceous to minute squamules. 



7. Spores 8, simple, colorless II. Dermatocarpon 



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

 EE. Apothecia not pyrenocarpous. 



/. 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. Calicium 



NN. Spores 4-8 celled VIll Stenocybe 



LL. Apothecia short-stipitate or sessile. 



