42 THE CHICAGO ACADEMY OF SCIENCES. 



118. V, fuscella, Fr. Thallus crustaceous, dark brown, areolate- 

 diffract. black- limitate, smooth: apothecia minute, immersed 

 in the areolae. Spores 8, colorless. Ach. L. U. 289. 



Found on detached calcareous rocks near Joliet; not common 

 as far as observed. A well defined and interesting species. 



119. V. muralis, Ach. Thallus whitish, tartareous, mealy or want- 

 ing; apothecia black, semi-immersed, hemispherical; peri- 

 thecium dimidiate. 



Found on limestone near Joliet and in Cook County, and 

 sometimes on old mortar. 



120. V. viridula, Ach. Thallus greenish olive, areolate-diffract, 

 areolae polygonal, smooth or rugose, effuse; apothecia black, 

 numerous, semi immersed. Spores 8, colorless. 



On detached calcareous rocks, north bluff at Lemont 



Pyrenula, (Ach., N. & H.) Tuckerm. Thallus hypophloeoid, sub- 

 cortical, rarely ektophlceoid, superficial; apothecia denudate, 

 perithecium black, ellipsoid-oblong, etc. 



121. P, gemmata, (Ach.) Naeg. Thallus whitish, thin; apothecia 

 black, medium to large, prominent, convex; perithecium 

 black, dimidiate. Spores colorless. Ach. Math. Lich. 120. 

 (1803). Acrocordia, K'br. 



On oaks and hickories at River Forest and in all our territory 

 This species is closely related to Sphaeria mastoidea, Fr. 



122. P, punctiformis, (Ach.) Naeg. Thallus thin, effuse, brown; 

 apothecia black, shining, minute, sessile-innate, conoid; peri- 

 thecium dimidace. V. epidermidis, Nyl. Offers a near ap- 

 proach to Fungi according to Fries, Wallroth, Tuckerman. 



On Quercus alba near Elgin and elsewhere. 



123. P, thelaena, (Ach.) Tuckerm. Verrucaria, Ach. 



On birch trees at Glencoe; on maples and hickories near River- 

 side. 



