56 4. PYRENULACEAE [ 21. Belonia 



1. Clathroporina amygdalina (Mull. Arg.) Fink n. comb. 



Porina amygdalina Mull. Arg., Hedwigia 34:34. 1895. 



Superficial thallus thin, in small or larger areas, smooth, somewhat shining, 

 greenish gray, varying toward ashy or yellowish; perithecia small, oblong, 0.15-0.3 

 X 0.25-0.5 mm. across, superficial portion convex, black; spores oblong-ovoid, 

 8-12-septate transversely and 2-3-septate longitudinally, 22-37 X 11-18 /a. 



On trees, Louisiana. 



21. Belonia Koerb., in T. Fries, Gener. Heterol. 105. 1861. 



Thallus forming a very thin to thin, smooth crust over the substratum, partly 

 or wholly within the substratum, devoid of differentiation into layers; perithecia 

 minute to small or middle-sized, more or less immersed in thalloid warts, the 

 superficial portion a black apex, the ostiole minute to rarely larger, the wall com- 

 plete, thick above and thin below; paraphyses threadlike, unbranched, sometimes 

 indistinct; asci cylindrico-clavate, soon breaking down; spores 4- commonly 8, 

 hyaline, acicular, many-septate, the cells cylindrical. 



The algal host is Trentepohlia. 



1. Belonia americana Fink; Hedrick, Mycologia 25:309. 1933. 



Thallus very thin to thin, smooth, ashy gray to whitish; perithecia small to 

 middle-sized, 0.3-0.8 mm. across, partly immersed, covered by a thin, whitish 

 thalloid veil, the apex visible, black, sometimes surrounded by a white border, the 

 ostiole minute, usually invisible, and sometimes covered by a white layer, the wall 

 complete, thick above and thin below; hypothecium tinged brownish; hymenium 

 hyaline; spores 8, long-acicular, reaching 39-44-septate, 170-250 X 2-3 /x, parallelly 

 arranged. 



On trees, Texas. 



22. Thelopsis Nyl., Mem. Soc. Sci. Nat. Cherb. 3:194. 1855. 



Thallus forming a thin, smooth to more or less rough crust upon the substratum, 

 partly or wholly within the substratum, devoid of differentiation into layers; peri- 

 thecia minute, more or less immersed in thalloid warts, the wall thin, brownish to 

 black, complete, the superficial portion a black apex, the ostiole minute, puncti- 

 form; paraphyses slender, unbranched; asci cylindrico-clavate; spores many, hya- 

 line, ellipsoid to oblong-ellipsoid, 1-3-septate, rarely non-septate, the cells cylindri- 

 cal. 



The algal host is Trentepohlia. 



1. Thelopsis subporinella Nyl.; Hasse, Bull. Torr. Club 25:632. 1898. 



Dithelopsis subporinella (Nyl.) Clements. 



Thallus composed of small, irregular warts, scattered or crowded together into 

 an uneven, chinky, reddish yellow or buif-colored crust; perithecia minute, 0.1-0.25 

 mm. across, immersed 1-several in the thalloid warts, the ostiole scarcely visible, 

 indicated by a minute light brown area; hyaline within; spores oblong-ellipsoid, 

 1 -septate, 8-15 X 4-8 fx. 



On trees, southern California. 



23. Pyrenula Mass., Ric. Lich. 162. 1852. 



Thallus forming a thin, smooth to rough crust upon the substratum, partly or 

 wholly within the substratum, devoid of differentiation into layers; perithecia 

 minute to small or middle-sized, more or less immersed to adnate, the superficial 

 portion hemispherical to conical, the ostiole minute, often rarely visible, the wall 

 thin and complete or dimidiate; paraphyses unbranched; asci clavate; spores 8, 

 brown, ellipsoid, oblong or pointed-ellipsoid, 3- rarely 5-7-septate, the cells len- 

 ticular. 



The algal host is Trentepohlia. 



A. Spores 3-septate 



B. Perithecia minute, not more than 0.4 mm. across 



C. Thallus commonly indicated by a coloration of the substratum 



D. Thallus a whitish or yellowish coloration 1. P. aspistea 



