34 THE CHICAGO ACADEMY OF SCIENCES. 



Myriangium, Mont, and Berk. Thallus cellulose, orbiculate, 

 plicate -striate at the circumference, nodulose; apothecia 

 lecanoroid. Spores oblong-ovoid. 



87. M. duriaei, (M. & B.) Tuckerm. Thallus crustaceous, adnate, 

 becoming free, fuscous; apothecia elevated, blackish, disk 

 with depressed, entire margin. Tuck. Gen. L. 140. M. 

 curtisii, M. & B. 



Collected several years ago on Corylus near River Forest; 

 not observed elsewhere. Common south. Its position 

 among the lichens is considered doubtful. 



FAMILY 8. LECIDEEI. 



Biatofa, Fr. Thallus various or deficient; apothecia diverse in 

 color, becoming soft and swollen when wet. Spores ellipsoid 

 and simple, or assuming different forms, colorless, numerous. 



88. B, coarctata, (Ach.) Th. Fr. Thallus cinereous, of minute 

 squamules, rimose-areolate; apothecia small, fuscous or black- 

 ish, connivent or open, sometimes flat. Spores ovoid-ellipsoid. 

 Lecidea, Nyl. Scand. 196. Tuck. Syn. Pt. 2. 15. Parmelia, 

 Fr. L. E. 104. 



On calcareous and arenaceous rocks in Will County; also 

 found on detached sandstones in Cook County. A widely 

 distributed and variable species. 



89. B, varians, Ach. Thallus of minute granules compacted 

 into a yellowish or greenish crust, which is granulate or 

 broken; apothecia very small, yellowish, rufous or black- 

 ish; disk flat, margin thin. B. exigua, (Chaub. ) Fr. L. E. 



278. 



On oaks and hickories near Elgin and Leniont. 



90. B, rubella, (Eh rh.) Rabenh. Thallus yellowish or grayish-green, 

 effuse, confluent; apothecia luteo-rufescent, or reddish-brown; 

 scattered or congregate, becoming tumid and margin excluded, 

 the latter often whitish. Spores pluri-locular. Lecidea, 

 Schaer. Spicil. 168. Bacidia, Th. Fr. Scand. 344. Biatora, 

 Tuck. Syn. Pt. 2. 44. 



