384 HERRE 



excluding the entire, thin, elevated margin. " Spores oblong, 

 the sporoblasts approximate, the isthmus deficient, ~ mic. 

 The biatorine apothecia bordered more or less, or coronate, 

 with the finally powdery nodules of the thallus ; 1-2 mm. wide." 



The above description but little altered from Tuckerman's 

 excellent diagnosis. 



Very abundant on sandstone ledges from Pescadero Point 

 southward along the coast to Pigeon Point. It grows usually 

 within a few feet of the water, barely above ordinary high tide, 

 and must be submerged at every storm or unusual tide. 



Identification by the author. 

 Placodium coi'alloidcs Tuck. Proc. Am. Acad. 6: 287. 1864; 



Syn. N. Am. Lich. i : 169. 1882. 



XVIII. Lecanora (Ach.) Tuck. 



Thallus typically crustaceous and uniform ; in some species 

 lobed and sub-foliaceous and in a few Californian species fruti- 

 cose. Apothecia (in the present species) sub-pedicellate, termi- 

 nal or sub-terminal ; the spores simple, colorless, ellipsoid. 



A strict interpretation of this genus will undoubtedly exclude 

 certain sections of the* group as interpreted by Tuckerman, e. 

 g.^ Acarospora. 



Lecanora Ach. Lich. Univ. 77. 1810; in part. 

 Lecanora Tuck. Gen. Lich. no. 1872 ; Syn. N. Am. Lich. i : 



181. 1882. 



KEY TO THE SPECIES. 



a. Species fruticose, stout, short, erect; on rocks. 

 b. Apothecia abundant, terminal or sub-terminal. 



c. Disk yellowish, tawny, dusky, or black i. boIanderi\ 3S4. 



CO. Disk pale yellowish to tawny red 3. thavitiitis^ Z^S' 



bb. Sterile. (Apothecia lateral when present, with pale-brick- 

 colored disk) 3. phryganitis^ 2>^S' 



I. LECANORA BOLANDERI Tuck. 



Thallus fruticose, short, rigid, dichotomously divided, form- 

 ing dense clumps ultimately ; branches terete, erect, blunt ; 

 color a yellowish green. Apothecia terminal, medium size, be- 

 coming large; disk concolorous or decidedly yellowish, some- 



