GENERA AND SPECIES. 109 



bose, attached by a narrow neck. Disk yellowish or 

 tawny. Spores as in B. mixta. 



5. Bacidia, 



This genus is represented by a considerable num- 

 ber of species and is well characterized, although some 

 authors include it under Biatora, no doubt because in 

 its gross characters it resembles that genus. 



The thallus is typically crustose, sometimes becom- 

 ing indistinctly areolate or coarsely granular, color 

 gray to greenish. The alga? are Proto§occus. The 

 apothecia are of medium size. Disk convex to flat- 

 tened, light-brown to black ; the hypothecium varies 

 from dark-brown to nearly black. Tlie spores are 

 much elongated, acicular, more narrow toward one 

 end, colorless, five to eleven-celled, variable in size and 

 form. 



This genus is southern in its range. They generally 

 occur upon tree-trunks, more rarely upon rock and 

 moss. 



1. Bacidia albescens. Thallus thinly granular, green- 

 ish to gray. Apothecia small. Disk convex, pale-yel- 

 lowish or pale-brown. Spores very slender, indistinctly 

 septate, 35/t X 1.8//,. 



2. Bacidia cuprea-rosella. Thallus granular to squa- 

 mose, light-gray to greenish-gray. Apothecia small. 

 Disk convex, yellowish to reddish-brown. Spores 

 comparatively short and thick, usually blunt at both 

 ends, five-celled, colorless, 17/x X 3/4,. 



3. Bacidia chlorosticta. Thallus deficient, minutely 

 granular, gray to greenish. Apothecia very small. 



