DIDERMA 131 



white, fragile, crustaceous, soon breaking about the margins, closely- 

 applied to the inner, which is delicate, cinereous and ruptures irreg- 

 ularly; stipe about equal to the diameter of the sporangium, 1 mm., 

 rather stout, calcareous, nearly white or pallid to brownish or aluta- 

 ceous, more or less wrinkled longitudinally, the wrinkles, when present, 

 forming veins on the lower surface of the sporangium; hypothallus 

 small; columella not distinct from the thickened brownish or reddish 

 base of the sporangium; capillitium of delicate threads, mostly simple 

 and colorless, often scanty; spores pale violaceous, nearly smooth, 

 8-9 ix. Plasmodium opaque white. 



A very well-marked species, easily recognized, at least when stip- 

 itate, by its remarkable discoid or lenticular sporangia. The name 

 hemis pharicum is unsuitable, as the sporangia are not hemispherical. 

 After the spore dispersal, the stipes are long-persistent, surmounted 

 by a peculiar disk representing the consolidated columella, lower 

 sporangial wall, and expanded stem-top. Sessile specimens are like 

 similar forms of D. reticulatum, but in all the gatherings before 

 us the stipitate type is at hand to reveal the identity of the 

 species. 



Rostafinski's figs. 131, 146, 149, and 150, adapted from Corda, 

 exaggerate the hypothallus, but otherwise leave nothing to be desired. 



As to synonymy, Bulliard has plainly the priority. His figure, 

 pi. 446, fig. 1, can refer to nothing else, especially reenforced as it is 

 by Sowerby, Eng. Fung. PI. 12. 



Rather rare on fallen stems of herbaceous plants, but widely dis- 

 tributed, New England to Oregon and Washington, Puerto Rico, 

 Argentina; Europe, South Africa, Ceylon, Java, Japan. 



13. Diderma montanum Meylan 



Bull. Soc. Vaud. Sc. Nat. 53 : 454. 1921. 

 PL IX, Figs. 198, 199. 



1910. Chondrioderma montanum Meyl., Bull. Soc. Bot. Geneve 2 : 262. 



Sporangia scattered or in groups, subglobose, stalked, flattened or 

 umbilicate beneath, pearl or pinkish gray or nearly white, smooth or 

 somewhat wrinkled, 0.6-0.8 mm. in diameter; sporangium wall of two 

 often separating layers, the outer densely charged with lime granules, 

 the inner reddish brown throughout or towards the base; stalk pale 

 or bright brownish yellow, slender or stout, enclosing white lime de- 

 posits, 0.1-0.8 mm. high; columella small, globose or hemispherical, 

 brownish red, sometimes stalked; capillitium of slender purplish or 



