134 



GEOLOGY OF LA SALLE COUNTY. 



ticulose, cortical layer distinct, gonimia in chains, 

 apothecia sub-scutellaeform, lecanorine or sub- 

 biatorine. Spores of various forms. 

 L. lacerum, Sw., Nyl. Thallus plumbeo-fusces- 

 cent, lacero-laciniate, ample, wrinkled, the lobes 

 dilated above and sinuate, thin, crisped and den- 

 tate,, apothecia small, pale red, sub-sessile, 

 margin entire. Spores avoid-ellipsoid. Ach. 

 Iv. U., 657. On elms and rocks. Deer Park 

 timber, 



Ij. chloromelum, Sw., Nyl. Thallus small to large, 

 orbiculate, rigid, plumbeo-virescent, lobate, pli- 

 cate, rugose, apothecia medium size, lecanorine, 

 plane, rufous, the thalline margin granulate. 

 Spores ovoid. Nyl. Syn., 128. On ash and 

 elm and rocks. 



Iv. myochroum, Ehrh. Schsrer, Tuckerm. Thal- 

 lus ample, coriaceous, membranaceous, sub-mon- 

 ophyllous, also loosely attached, lead colored 

 and blackish, beneath has a whitish nap, apo- 

 thecia reddish, border plicate. Spores ellipsoid. 

 Tuck. 99. On calcareous rocks on the Big Ver- 

 million, also on trees. 



L. pulchellum, Ach., Nyl. Thallus small to large, 

 rosulate, glaucous green, lobes plicate, papu- 

 lose, wrinkled above and beneath and pitted, 

 apothecia medium size, lecanorine, sub-pedicel- 

 late, disk fusco-rufous, finally excluding the 

 smooth or finally rugose thalline margin. Spores 

 ovoid-ellipsoid, sub-muriform, decolorate. Col- 

 lema, Ach. 



LECANOREI. 



PLACODIUM, D. C, Naeg. & Hepp. Thallus crus- 

 taceous, lobed, sufFruticulose, or uniform, apo- 



