40 HERRE 



continuous crust, chaffy or microscopically corallinoid, dingy brown 



in color; resembling a crustaceous Pannaria or Collemaceous lichen. 



Apothecia not numerous or conspicuous, small, black, semi-im- 



mersed; spores larger than in the previously described form, . ? fx. 



24-30 



In other respects agreeing. 



Unlike anything in the accessible literature or specimens, and per- 

 haps new. 



2. VERRUCARIA VIRIDULA Ach. 



Verrucaria viridula Acharius, Lich. Univ. 675. 1810. 



Thallus forming a thickish, effuse, rough or uneven, chinky or 

 fissured crust of minute, polygonal areoles, closely compacted; their 

 surface smooth or rough or warty; color varying from pale to dark 

 olive blackish brown, with a more or less evident greenish cast when 

 wet; KOH-; CaCl30,-. 



Apothecia usually but one in an areole, rather large,black, immersed, 

 with only the apical portion visible; usually without an ostiolum; 

 perithecium dimidiate, thick, black; amphithecium thin, black; 

 hymenial gelatine bluish with I; spores broadly elliptical, colorless, 



I2i — I?? 



often with one or two very large oil drops, — ~ fi. 



24 - 34 



Abundant on sandstone in the foothills and probably occurring all 

 through the mountains. 



A plant of Europe, North America, and northern Africa. 



3. VERRUCARIA NIGRESCENS Pers. 

 Verrucaria nigrescens Persoon, Ust. Ann. Bot. 14: 36. 1795. 



Thallus effuse or sub-determinate, thin or becoming moderately 

 thick, of minute areoles, compacted into a nearly uniform crust; color 

 dark brown to black. 



Apothecia numerous, of moderate size, hemispherical, more or less 

 immersed and with the apex often covered by the thallus; the apical 

 pore usually not visible; perithecium entire; hymenial gelatine pale 

 salmon or reddish with I, or part reddish and part blue with I; spores 

 ellipsoid to short and broadly ovate, often falsely bi-nucleolate or 



