214 PERTUSARIA. 



small to almost middling-sized, adnate ; monothalamous ; the 

 dilated, discoid ostiole yellowish-powdery, little exceeded by the 



margining portion. Spores in twos and threes ; " ^ mic. Obs. 



Lich. 4, L c. p. 177. 



Rocks, San Diego, California, Dr. Cooper. Fruit rarely 2- 



thalamous. 



t Spores bilocular. 



9. P. rhodocarpa, Koerb. ; thallus membranaceous ; from 

 greenish-glaucescent becoming white ; and densely granulate ; 

 apothecia small, sub-sessile, sub-globose ; from mono- at length 

 2-3-thalamous ; bursting from the first into* soredia, and the 

 thalline exciple soon obsolete ; disk flesh-coloured, concealed by 

 a white powdery veil, but afterwards, as this disappears, red- 

 dish-dotted. Spores solitary ; ^"^ mic. Koerb. Syst. p. 384. 



Tuckerm. Gen. p. 128. Varicellaria, Th. Fr. Scand, p. 322. 

 V. microsticta, Nyl, Scand. p. 183. *.!,/. 8. 



On bark. Arctic America, Nylander Scand. 1861. British 



Columbia, Macoun. The apothecia differ in no respect from 



others of forms of P. multipuncta, also at length " reddish- 

 dotted," except in the spores being bilocular. 



* * Apothecia compound, difform. 



10. P. communis, DC. ; thallus cartilagineous, from smooth 

 and even becoming chinky and rugose-verrucose ; glaucescent ; 

 now zonate at the circumference ; apothecia small to middling- 

 sized, adnate, depressed - sub-globose and variously difform; 

 closed except at the sunken, and for the most part blackening, 

 and numerous ostioles. Spores solitary ; or in twos ; very rarely 



in threes and fours; ^'^ 7 mic. Porina pertusa (L.) Ach. Syn. 



p. 109. Pertusaria, Tuck. Syn. N. E. p. 84. P. communis, Nyl. 

 Scand. p. 178. Th. Fr. Scand. p. 317. 



Trunks and rocks. Northern and middle States, Muhlenberg 

 Catal. 1818. Canada, Macoun. Ohio, Lea. Illinois and Mis- 

 souri, Hall. Virginia, Tucker man. North Carolina, Curtis. 

 South Carolina, Ravenel. Alabama, Peters. Texas, Wright. 

 California, Bolander. 



11. P. leioplaca (Ach.) Scha3r. ; thallus cartilagineous, rather 

 thin, becoming chiuky and rugged; glaucescent, and pale- 

 yellowish ; apothecia small to middling-sized, adnate, globular 



