280 36. ACAROSPORACEAE [ 138. Biatorella 



A. On rocks 



B. Thallus poorly developed and rarely persistent except 

 under the apothecia 

 C. Spores numerous, not more than 8 n in length 



D. Apothecia pruinose 11. B. simplex pruinosa 



D. Apothecia not pruinose 



E. Apothecia 0.2-1 mm. across, red when wet .... 11. B. simplex 

 E. Apothecia 0.7-2 mm. across, not red when wet ... 10. B. clavus 



C. Spores not numerous, 8-16 X 3-6.5 /i 12. B.revertens 



B. Thallus well developed and persistent 



D. Thallus granulose, greenish gray to gray 16. B. hypophaea 



D. Thallus areolate, yellowish copper-colored and 



blackening 7. B.testudinea 



1. Biatorella geophana (Nyl.) Rehm, in Rabh., Krypt. Flora Deutsch. ed. 2. 



1:307. 1890. 

 Lecidea geophana Nyl., Not. Sallsk. Faun. Flor. Fenn. 5:212. 1861. Biatora 



geophana (Nyl.) T. Fries. 

 Thallus greenish gray, very thin, evanescent; apothecia minute, 0.15-0.3 mm. 

 across, the disk convex, black, the exciple soon disappearing; hypothecium yellow- 

 ish brown; asci ventricose; spores 12-18, spherical, 5-7.5 p in diameter. 

 On soil and rotten wood, Massachusetts, New Jersey, and Illinois. 



2. Biatorella resinae (E. Fries) T. Fries, Nov. Act. Soc. Sci. Ups. III. 3:299. 



1861. 

 Peziza resinae E. Fries, Syst. Myc. 2:149. 1822. Biatora difformis (E. Fries) 



Tuck. 

 Thallus thin, yellowish to grayish or brownish, scurfy, evanescent; apothecia 

 small to middle-sized, 0.4-1 mm. across, sessile, the disk flat to convex, pale to 

 yellowish and finally blackening, the exciple of the same color, and soon disappear- 

 ing; hypothecium from yellowish to brown; asci clavate-ventricose ; spores spheri- 

 cal, 2-3.5 /a in diameter. 



On pine resin, Vermont, Massachusetts, New York, and New Jersey. 



3. Biatorella nannaria (Tuck.) Zahlbr., Cat. Lich. Univ. 5:44. 1927. 

 Heterothecium nannarinm Tuck., Gen. Lich. 176. 1872. 



Thallus thin, scurfy-granular, pale lemon-colored; apothecia minute, 0.15-0.25 

 mm. across, sessile, the disk fiat to slightly convex, reddish brown, the exciple 

 thin, yellow; hypothecium dusky brown; asci short and swollen; spores spherical, 

 2-2.5 p. in diameter. 



On trees, Texas. 



4. Biatorella Rappii Zahlbr., Ann. Mycol. 29:82. 1931. 



Thallus very thin, smooth, widespread, continuous, dirty brown; apothecia 

 minute, 0.3-0.5 mm. across, adnate to sessile, slightly constricted at the base, more 

 or less scattered, the disk deeply concave to concave or rarely flat, reddish brown, 

 the exciple thick, colored like the disk; hypothecium hyaline to yellowish or 

 tinged reddish brown; asci fusiform to clavate; spores globose, 2-3 yu. across. 



On trees, near Mecca, Florida. 



5. Biatorella conspersa (Fee) Vainio, Act. Soc. Faun. Fl. Fenn. 7:62. 1890. 

 Lecidea conspersa Fee, Essai Crypt. 108. pi. 27, f . 4. 1824. 



Thallus of very minute, crowded or scattered, yellowish gray to orange-yellow 

 granules; apothecia small, 0.5-1 mm. across, sessile, the disk orange to black, pow- 

 dery-granular, flat to strongly convex, the exciple pale yellow, becoming blackish 

 where rubbed, soon disappearing; hypothecium reddish to blackish brown; spores 

 spherical, 1.5—2.5 ^t in diameter. 



On trees, southern Alabama. 



6. Biatorella moriformis (Ach.) T. Fries, Lich. Scand. 1:401, 402. 1874. 

 Arthonia moriformis Ach., Syn. Meth. Lich. 5. 1814. 



Thallus of minute granules, commonly compacted into a thin, smooth, wide- 



