138 



GEOLOGY OF LA SALLE COUNTY. 



sandstone at various points. 



L. privio-na, Ach., Nyl., var. pruinosa, Auctt, 

 apothecia small, appressed, sunken, disk gray- 

 pruinose. Sarcog-yne, Koerber, Lecanora, Nyl. 

 On Trenton rock at Eton's mill. 



Iv. perproxima, " Nyl. Spec. nova. Resembles L. 

 erysibe, Ach. , nevertheless the spores are laro-er. 

 .014-18 by .007mm., and the hyraenial gelatine 

 with iodine is a beautiful blue, becoming deep 

 blue. In appearance it resembles L. caesio-cine- 

 rea, Nyl. On calcareous rocks on the Vermil- 

 lion, at Eton's and Bailey's. New to science. 

 W. W. C. discoverer. 



Iv. erysibe, Ach. Thallus cinerous, thin, diffract, 

 apothecia fusco-rufous, plane or conA^ex. On 

 calcareous rocks ^t Eton's and elsewhere. 

 PERTUSARIA, D. C. Thallus crustaceous, contin- 

 uous, smooth or verrucose, apothecia g-lobular, 

 difform, closed, enclosed in thalline verrucae, 

 opening by pores (ostioles), explanate, lecano- 

 roid. Spores generally large, ellipsoid. 



P. velata. Turn., Nyl. Thallus white, glauces- 

 cent, rugose, chinky, rimose, radiate near the 

 circumference, apothecia small, adnate, pale 3^el- 

 lowish, white powdery, the thalline margin dis- 

 appearing in the fruit. On rocks and trees . 



P. communis, D. C. Thallus glaucescent, smooth, 

 chinky or rugose-verrucose, may become zonate 

 at the circumference, apothecia small, adnate, 

 depressed, sub-globose, difform, closed, the 

 numerous ostioles sunken and black. Spores 

 generally in twos, sometimes solitary. Porina 



*L. perproxima. Nyl. Spec. Nova. Proxima. L. erysibe. Ach. Sporisnonni- 

 hil majoribus. long, 0014-lb crass. 0.007 millim., et gelatiua hymenialis. lodo 

 l>ene-coerules- ceiite. coerulescentia persistente. F'acies fere Lecan(.ra caesio- 

 cinerea, Nyl. 



