146 



GEOLOGY OF LA SALLE COUNTY. 



cies, two so abundant as to be easily identified. 



A. lecideella, Nyl. Thallus green, uneven, effuse, 

 apothecia abundant, small, round, plain, prui- 

 nose. Spores oblong'-ovoid. On hickories and 

 Crataeg'us throug-hout our territory. 



A. spectabilis, Pi. Thallus thin, white, apothecia 

 black, difform, ang-ulate, plain or convex, often 

 bordered by the thallus. A. dispersa, Duf. A. 

 polymorpha, of Mulil. Catal. 1818. On maples. 

 It is also found on other trees. Synonyms 

 numerous. 



A. diffusa, Nyl. Thallus white, effuse or w^anting-, 

 apothecia round or difform, plane or convex, 

 pruinose. On hickories and maples. 



A. radiata, Pers., Th. Fr. Thallus whitish, dark- 

 ening-, or obsolete, apothecia dark brown, stel- 

 late, difform or ramulose, erumpent. Ope- 

 g-rapha, Pers. (1794). Arthonia, Th. Fr. Arc- 

 tic, 240. A. astroidea, Ach. Syn. 6. Has many 

 synonyms, and until lately was known as A. 

 astroidea, Ach. Found on oaks. The variety 

 swartziana, Nyl. should also occur within our 

 limits. 



A. taediosa, Nyl. Thallus indeterminate, apothecia 

 erumpent, linear, heaped, few^ branched and 

 sometimes round. On maples, also on oaks. 

 The name is very applicable. 



TRIBE IV. 



CALICIUM, Pers., Ach., Fr. 



C. subtile, Fr. Apothecia turbinate, stipitate. On 

 dead wood, Baldwin farm. 



