DIDERMA 10 1 



like thickenings, all sparingly branched ; spores violet brown, 

 minutely roughened, 9-10 /A. 



We have seen no specimens of this species. It is here in- 

 cluded on the authority of Lister's Monograph, as providing 

 a place for Phillips's species, sure to be seen again when the 

 cryptogamic flora of the Sierras shall be better known. 



California. 



10. DIDERMA CINEREUM Morgan. 



1894. Diderma cinereum Morgan, Jonr. Cin. Soc., p. 70. 



Sporangia gregarious, more or less crowded or even confluent, 

 sub-globose, only slightly depressed, ashen white ; the peridium 

 not obviously double, very smooth and thin, rupturing irregu- 

 larly ; hypothallus an indistinct membrane or wholly wanting ; 

 columella large, globose or hemispheric, white, the surface granu- 

 lose; capillitium of very slender colored threads, the extremities 

 pellucid, more or less branched ; spores violaceous, minutely 

 warted, 9-1 1 p. 



Growing on old wood, leaves, etc. The sporangium .3-. 5 mm., 

 thin and smooth or rugulose. This elegant little species I know 

 only from specimens received from Mr. Morgan. It seems to be 

 closely related to D. spmnarioidcs, from which it is distinguished 

 by its color, darker, and its smoother or less spinulose spores. 

 The author compares the color and external appearance to that 

 of P. cinereum, --Jour. Cin. Soc., XVI., p. 154- 



Ohio, Pennsylvania. 



n. DIDERMA HEMISPHERICUM (Bull.') Home. 



1791. Reticularia hemispherica Bull., Cham, de Fr., I., p. 93. 



1829. Didymium hemisphericum (Bull.) Fr., Syst. Myc., III., p. 115. 



1829. Diderma hemisphericum (Bull.) Home., Fl. Dan., XL, p. 18. 



1832. Didymium michclii Lib., PL Ard., No. 180. 



1873. Chondrioderma michelii (Lib.) Rost, Fuckel, Sym. Myc., p. 74. 



Sporangia gregarious, orbicular, discoid, depressed above and 

 often umbilicate below, stipitate or sometimes sessile, the outer 

 peridium white, fragile, crustaceous, soon breaking about the 



