102 THE NORTH AMERICAN SLIME-MOULDS 



margins, closely applied to the inner, which is delicate, cinere- 

 ous, and ruptures irregularly ; stipe about equal to the diameter 

 of the sporangium, i mm., rather stout, calcareous but colored, 

 brownish or alutaceous, 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 /JL. 



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

 stipitate, by its remarkable discoid or lenticular sporangia. 

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

 mounted by a peculiar disk representing the consolidated colu- 

 mella, lower sporangial wall, and expanded stem top. Sessile 

 specimens are like similar forms of D. rcticulatum, but in all 

 the gatherings before us the stipitate type is at hand to reveal 

 the identity of the species. 



Rostafinski's figures, 131, 146, 149, and 150, adapted from 

 Corda, exaggerate the hypothallus, but otherwise leave nothing 

 to be desired. 



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

 figure, t. 446, Fig. i, can refer to nothing else, especially re- 

 enforced as it is by Sowerby, Eng. Fung., t. 12. 



Rather rare on fallen stems of herbaceous plants, but widely 

 distributed, New England to Oregon and Washington. 



12. DIDERMA TREVELYANI (Grcv^] Fries. 



1825. Leangium trevelyani Grev., Scot., Cr. Fl., tab. 132. 



1829. Diderma trevelyani (Grev.) Fries, Sys. Myc., III., p. 105. 



1875. Chondrioderma trevelyani (Grev.) Rost., Mon., p. 182 



1877. Diderma geaster aides Phill., Grev., V., p. 113. 



1877. Diderma laciniatum Phill., Grev., V., p. 113. 



Sporangia scattered, globose or nearly so, smooth or verrucu- 

 lose, reddish brown or rufescent, sessile or short-stipitate, the 

 outer peridium firm, splitting more or less regularly into un- 

 equal, revolute, petal-like lobes which are white within, the 

 inner not distinguishable as such ; stipe, when present, equal, 



