142 HERRE 



Thallus small, suborbicular to effuse, appressed, with upturned 

 edges; lobes rounded, more or less complicate; margin entire, crenate, 

 or somewhat laciniate; greenish lead-color to brown. 



Apothecia numerous and comparatively large, reddish brown; 



10 16 



margin entire, paler; spores muriform, - //. 



24 - 40 



On earth, among mosses. 



On clay banks beside roads, on Black Mountain and probably 

 elsewhere in similar situations. From its smaD size too readily over- 

 looked. Distribution general in Europe. 



6. LEPTOGIUM TENUISSIMUM (Sm.) Korb. 



Collema tenuissimum Sm. Eng. Fl. 5: 213. 1795. 

 Leptogium tenuissimum Korber, Syst. Lich. Germ. 419. 1855. 

 Leptogium tenuissimum Tuck. Syn. N. Am. Lich. I: 157. 1882. 

 Leptogium tenuissimum Cummings and Seymour, Decades of N. Am. 



Lich. no. i25b, Mt. Tamalpais, Marin Co., Calif. 



Thallus minute, diffuse, irregularly cut and divided; foliaceous to 

 densely crustose; the lobes unequal, dissected, or crenately incised, 

 ascendant; color pale greenish brown to olive and dark brown or 

 chestnut. 



Apothecia numerous, appressed, comparatively large, reddish 

 brown, urceolate, the margin thick, entire; spores muriform, ovoid to 



oblong, apically attenuate, ^^ . 



24 - 39 



On earth and mossy roots; in the mountains at 1500 feet elevation 

 and above. Generally distributed over Europe and temperate 

 America. 



I also doubtfully refer here a very minute Leptogium occurring on 

 sandstone in the mountains above Saratoga, at an elevation of 2000 



feet; spores 3-septate or ovoid muriform, - - //. 



21 28 



