15. Arthopyrenia ] 4. PYRENULACEAE 47 



3. Arthopyrenia subprostans (Nyl.) Mull. Arg., Flora 66:317. 1883. 



Verrucaria subprostans Nyl., Mem. Soc. Acad. Maine et Loire 4:56. 1858. 

 Pyrenula subprostans (Nyl.) Tuck. 



Thallus rudimentary, the imbedded portion indicated by a widespread, whitish, 

 sometimes disappearing area; perithecia minute to small, 0.1-0.3 mm. across, the 

 wall dimidiate, superficial portion depressed, subhemispherical, black, the ostiole 

 minute, sometimes indicated by a whitish area; spores 1 -septate, ellipsoid, 11-16 X 

 3-5.5 [x, irregularly arranged. 



On trees, South Carolina, Florida, and Texas. 



4. Arthopyrenia litoralis (Leight.) Arm, Berecht. Bayr. Bot. Gesell. 1:120. 1891. 



Verrucaria litoralis Leight., Brit. Spec. Angioc. Lich. 46. pi. 20, f. 2. 1851. 

 Verrucaria consequents Nyl. Verrucaria consequella Nyl. A. consequella 

 (Nyl.) Zahlbr. 

 Thallus very thin, smooth, grayish, sometimes disappearing; perithecia minute, 

 0.1-0.15 mm. across, partly immersed, the wall dimidiate, the superficial portion 

 subhemispherical, black; paraphyses scanty, sometimes distinct; asci clavate, swol- 

 len; spores 8, hyaline, ovoid to ovoid-ellipsoid, 1 -septate, one cell sometimes larger, 

 13-20 X 5-8 fi, irregularly arranged. 



On siliceous rocks and on barnacles, Massachusetts. 



5. Arthopyrenia halodytes (Nyl.) Arm, Bericht. Bayr. Bot. Gesell. 1:121. 1891. 



Verrucaria halodytes Nyl., Mem. Soc. Sci. Nat. Cherb. 5:142. 1857. 



Thallus thin, smooth to chinky and areolate, somewhat gelatinous, greenish 

 brown or blackish; perithecia minute, 0.1-0.25 mm. across, slightly immersed, very 

 numerous and somewhat crowded, the superficial portion hemispherical, black, the 

 ostiole rarely visible, indicated by a whitish area, the wall dimidiate; asci inflated 

 clavate; spores 8, hyaline, oblong, 1-septate, one cell slightly larger, 12-15 X 

 4.5-7 fi, irregularly arranged. 



On rocks along the coast, southern California. 



6. Arthopyrenia epidermidis (DC.) Mass., Ric. Lich. 167. f. 331. 1852. 



Verrucaria epidermidis DC, in DC. & Lam., Fl. Fr. ed. 3. 2:313. 1815. 



Thallus rudimentary, the superficial portion disappearing or absent, and the 

 imbedded portion indicated at the surface by smooth, grayish or brownish gray 

 areas; perithecia minute to small, 0.2-0.5 mm. across, partly immersed, the super- 

 ficial portion hemispherical, black, the wall dimidiate, the ostiole minute, sometimes 

 indicated by a whitish area; asci broadly clavate; spores 8, hyaline, 1-septate, 

 oblong or oblong-ellipsoid, sometimes slightly constricted, one cell larger, 16-25 X 

 5-7.5 fi, irregularly arranged. 



On trees, Louisiana and Ohio. 



There are specimens in herbarium under this name from California and Illi- 

 nois, but these specimens have 3-septate spores and much different-looking asci. 



7. Arthopyrenia cinereopruinosa (Schaer.) Koerb.. Syst. Lich. 368. 1855. 



Verrucaria cinereopruinosa Schaer., Lich. Helv. Spic. 6:343. 1833. 



Thallus thin, smooth, greenish gray to olivaceous; apothecia minute to small, 

 0.2-0.4 mm. across, wholly or partly immersed, when apparently pruinose from the 

 thalloid covering, black, dimidiate, the superficial portion hemispherical, the ostiole 

 umbilicate; spores 1-septate. narrowly ellipsoid, 12-17 X 3.5-5 fi, irregularly ar- 

 ranged. 



On trees, Santa Cruz Peninsula, California. 



8. Arthopyrenia Finkii Zahlbr., Cat. Lich. Univ. 1:306. 1921. 



A. macrospora Fink, Cont. U.S. Nat. Herb. 14:237. 1910, preoccupied by 



A. macrospora Stiz., Ann. Natur. Hist. Hofmus. Wien. 23:109. 1909. 

 Thallus widespread, very thin and disappearing, smooth, ashy white; perithecia 

 small to middle-sized, 0.4-0.75 mm. across, the wall dimidiate, superficial portion 



