128 19. LECANACTIDACEAE [69. Schismatomma 



black, finally disappearing; hypothecium dark brown; spores fusiform, sometimes 

 slightly curved, 3-septate, 18-24X4.5-6/*. 



On maritime rocks, Santa Cruz Peninsula, California. 



4. Lecanactis illecebrosa E. Fries, var. megaspora Merrill, Bryologist 16:59. 

 1913. 



L. amylacea var. megaspora (Merrill) Zahlbr. 



Thallus thin, more or less powdery or becoming granulose, white or grayish 

 white; apothecia small to middle-sized or larger, 0.4-1 mm. across, round, adnate, 

 the disk flat to convex, sometimes irregular, brown to black or whitish pruinose, 

 the margin thin, black, sometimes disappearing; hypothecium brownish black; 

 spores fusiform to oblong-fusiform, 3-septate, 24-30 X 4-6 /*. 



On trees, Washington. (The species is limited to Europe.) 



69. Schismatomma Flot. & Koerb., in Mass., Ric. Lich. 55. 1852. 



Thallus crustose, thin, smooth to chinky, powdery, or minutely granulose, rudi- 

 mentary, showing little or no differentiation into layers, attached to the substratum 

 by rhizoids; apothecia minute or small to middle-sized or larger, round, oblong, or 

 irregular, adnate to sessile, the disk flat to more or less convex, the exciple colored 

 like the thallus, thin to thick, irregular; hypothecium dark brown to brownish 

 black; hymenium hyaline to brownish above; paraphyses branched and netlike 

 interwoven; asci clavate; spores 8, hyaline, fusiform to oblong-fusiform or acicular, 

 sometimes curved, 3-13-septate, the cells cylindrical. 



The algal host is Trentepohlia. 



A. Spores 3-5-septate 



B. Spores constantly 3-septate 



C. Spores not more than 20 /* in length 



D. Apothecia 0.2-0.5 mm. across 2. S. ocellatum 



D. Apothecia more than 0.5 mm. across 6. S. vernans 



C. Spores more than 20 /i in length 



D. Thallus smooth to chinky, sometimes powdery . . .1. S.abietinum 

 D. Thallus chinky or granulose 



E. Apothecia 0.15-0.4 mm. across 3. S. pericleum 



E. Apothecia 0.6-1.3 mm. across 4. S. Ravenelii 



B. Spores 3-5-septate 5. S. subattingens 



A. Spores 7-more-septate 



B. Spores 7-septate, 25-30 /jl in length 7. S. hypothallinum 



B. Spores 7-13-septate, 40-50 m in length 8. S. pluriloculare 



1. Schismatomma abietinum (Ehrh.) Mass., Ric. Lich. 56. f. 102. 1852. 

 Lichen abietinus Ehrh., Plant. Crypt. Exsicc. 166. 1785. Pyrenothea leucoce- 



phala (Ach.) E. Fries. Lecanactis abietina (Ehrh.) Koerb. 



Thallus thin, greenish gray, smooth to chinky, sometimes powdery; apothecia 

 middle-sized or larger, 0.6-2 mm. across, round or becoming irregular or angular, 

 sessile, the disk flat to convex, densely whitish pruinose or rarely becoming black, 

 the exciple thick, thinly whitish pruinose; hypothecium dark brown; spores oblong- 

 fusiform, 3-septate, 30-42 X 4-6 /*. 



On trees, California. 



2. Schismatomma ocellatum (Nyl.) Zahlbr., Cat. Lich. Univ. 2:560. 1924. 

 Platygrapha ocellata Nyl., Act. Soc. Sci. Fenn. 7:478. 1863. 



Thallus thin, smooth and chinky to rarely thicker, rough and minutely granulose, 

 pale greenish gray to whitish, upon a thin, blackening hypothallus; apothecia 

 minute to small, 0.2-0.5 mm. across, partly immersed to adnate, round to oblong, 

 the disk flat, brownish to black, the exciple thin, colored like the thallus, becoming 

 crenate, covering a thin proper one; hypothecium brownish black; spores fusiform, 

 3-septate, 16-21 X 3.5-5/*. 



On trees, South Carolina and Florida. 



