35. Mycoporum] 11. CALICIACEAE 67 



3. Mycoporellum californicum Zahlbr., Ann. Mycol. 10:363, 364. 1912. 

 Thallus very thin, smooth to slightly rough, ashy white, often disappearing and 



the imbedded portion indicated at the surface by an ashy white coloration; peri- 

 thecia small to middle-sized, 0.5-1.2 mm. across, partly immersed, the superficial 

 portion slightly convex, dull black, becoming irregular, the ostioles numerous, 20 

 or more, round to slightly irregular; spores oblong-ellipsoid, 1-3-septate, 16-21 X 

 5-6 /J.. 



On trees, southern California. 



4. Mycoporellum difforme (Minks) Fink n. comb. 



Mycoporum difforme Minks, in Willey, Enum. Lich. New Bedford, Mass. 32. 

 1892. Dermatina difformis (Minks) Zahlbr. 



Thallus very thin, greenish gray to ashy, smooth, or imbedded and indicated 

 by a whitish area; perithecia small, 0.3-0.5 mm. across, partly immersed, the 

 superficial portion round to oblong or irregular, strongly convex, becoming obscure- 

 ly papillate; spores 1-3-septate, ellipsoid, 16-27 X 5-9 p.. 



On trees, near New Bedford, Massachusetts. 



35. Mycoporum Mey., Nebenstud. 327. 1825. 



Thallus crustose, smooth to rough, rudimentary, partly or wholly within the 

 substratum, devoid of differentiation into layers; perithecia minute to small, more 

 or less immersed, the wall dimidiate or complete, the superficial portion convex 

 to subhemispherical or depressed, the ostioles several, papillate; hypothecium 

 hyaline; hymenium hyaline or brownish above; paraphyses disappearing or per- 

 sistent and branched and interwoven; asci cylindrico-clavate, the apical wall some- 

 what thickened; spores 6-8, hyaline to brownish, oblong-ellipsoid to ellipsoid, 

 transversely and longitudinally septate. 



The algal host is Palmella. 



A. Spores very large, reaching 100/u. or more in length ...... 2. M. ohiense 



A. Spores not so large, not more than 50 /z in length . 1. M. pyrenocarpum 



1. Mycoporum pyrenocarpum Nyl., Flora 41:381. 1858. 



M. pycnocarpum Nyl. Dermatina pyrenocarpa (Nyl.) Zahlbr. 



Thallus thin, smooth to rarely scurfy or warty, sometimes disappearing, ashy 

 gray; perithecia small, 0.4-0.5 mm. across, oblong to irregular, the superficial por- 

 tion convex to subhemispherical or often depressed, more or less distinctly papil- 

 late, black; hypothecium hyaline; spores 8, hyaline to brownish, oblong-ellipsoid, 

 7-9-septate transversely and 1-3-septate longitudinally, 33-46 X 13-19 /a. 



On trees, from Massachusetts to Florida and westward to Nebraska and Cali- 

 fornia. 



2. Mycoporum ohiense (Nyl.) Fink n. comb. 



M. pycnocarpum ohiense Nyl., Mem. Soc. Sci. Nat. Cherb. 5:135. 1857. 



Thallus thin, smooth to slightly rough, ashy gray, sometimes disappearing; peri- 

 thecia small, 0.3-0.5 mm. across, irregular, the superficial portion convex or some- 

 times depressed, more or less distinctly papillate, black; hypothecium hyaline; 

 spores 8, hyaline, oblong-ellipsoid, 7-11-septate transversely and 1-3-septate longi- 

 tudinally, 94-120 X 23-30 /x. 



On trees, North Carolina, Ohio, and California. 



OTHER SPECIES REPORTED 

 Mycoporum Eschweileri Miill. Arg. — Florida. 



11. CALICIACEAE 



Thallus crustose, partly within the substratum, rudimentary, inconspicuous 

 and sometimes disappearing to well developed, showing little or no differentiation; 

 stipes rudimentary to well developed, rarely wanting, rarely branched or forked; 



