136 



GEOLOGY OF LA SALLE COUNTY. 



squamaceous, of creiiate granules, crowded into 

 heap-like areoles, often dispersed, greenish-yel- 

 low, apothecia small, sessile, flat, yellow, thai- 

 line margfin granulate-crenate. Spores numer- 

 ous, simple and bilocular. Pr. L. E. 162- Nyl. 

 Scand. 141. On old rails. Deer Park and else- 

 where. 



IvECANORA, Ach., Tuckerni. Thallus crustaceous, 

 mostly uniform, apothecia scutellaeform, or zeo- 

 rine. Spores ellipsoid, or oblong. 



Iv. pallida, Schreb., Schasrer. Thallus thin, mem- 

 branaceous, smooth, cream-colored or darker, 

 apothecia sessile, tumid, whitish bufl^, white 

 pruinose, the entire margin disappearing. 

 Spores ellipsoid. Parmelia, Schaer. Spicil. 396. 

 On oaks and hickories. 



L. subfusca, L., Ach. Thallus whitish or cinera- 

 scent, smooth, rimulose, g'ranulate, verrucose, 

 soon diffract, apothecia plano-convex, disk fus- 

 cous, becoming black, often pruinose, the thai- 

 line margine entire, flexuous or crenate. Spores 

 ellipsoid. Parmelia, Schoer. Spicil. 389, etc. 

 Very common in our territory on oaks and other 

 trees and also on arenaceous rocks. There are 

 several varieties. 



Iv. subfusca, Iv., Ach., var. argentata, Ach. Apo- 

 thecia smaller, margin entire. Spores smaller. 

 Lich. Univ. Nyl. Syn. 393. Occasionally 

 found on shrubs and trees. 



L. subfusca, L., Ach., var. distans, Ach. Com- 

 mon on the same substrates as the preceding 

 forms, apothecia flat and pale, margin crenulate. 

 L. distans, Ach. L. U. 397. On trees. 



L. hageni, Ach. Thallus cinerascent, verruculose 

 or wanting, apothecia small or minute, crowded, 



