88 HERRE 



Thallus thick to moderately thin, determinate, limited by a 

 more or less evident black hypothallus, uniform crustaceous, of 

 flat areoles separated by minute fissures which later become broad 

 and conspicuous cracks; KOH -; CaCl 2 2 -; medulla without reaction 

 with I. 



Apothecia at first small and innate, then appressed and large 

 to very large, numerous, single and circular or usually grouped and 

 then angular, i to 2.5 mm. wide; disk at first flat, soon slightly' 

 convex, black; margin thin, persistent, slightly elevated; epithecium 

 brown; thecium colorless, 80 /* high, blue with I; hypothecium almost 

 colorless or faint yellowish-gray or yellowish-brown; asci inflated 



oblong-clavate; spores oblong ellipsoid, - - //. 



10 i4 



On sandstone; at Castle Rock, altitude 3000 feet, and elsewhere 

 along the summit of the ridge. 



A lichen of alpine regions and the cooler parts of Europe and 

 North America. 



15. LECIDEA PLATYCARPA Ach. 



Lecidea platycarpa Ach. Lich. Univ. 173. 1810. 



Lecidea platycarpa Tuck. Syn. N. Am. Lich. II: 73. 1888. 



Thallus ash-colored or leaden gray, indeterminate, uniform, thick 

 and tartareous, becoming more or less fissured, or thin and granulose 

 to finely pulverulent; no hypothallus evident; KOH ; CaCl 2 2 . 



Apothecia numerous, small, i to i mm. wide, appressed, scattered; 

 disk black, slightly papillate, flat; margin thin, becoming obsolete; 

 the younger apothecia show a spurious, thin thalline margin now 

 and then; margin slightly horny; epithecium brown, much narrower 

 than the hypothecium; paraphyses conglutinate; hypothecium 

 brownish-black or blackish-brown; asci ventricose; spores ovoid- 



ellipsoid, ig 7. 7 2 V 



On sandstone in Santa Cruz, altitude about 50 feet. A lichen 

 of the subarctic and temperate regions of Europe and America. 



In our plant the thallus is much more developed and the apothe- 

 cia smaller than in specimens gathered by me in the Alps. 



