100 THE NORTH AMERICAN SLIME-MOULDS 



1873. Chondrioderma testaceum (Schrad.) Rost., Vers., p. 13. 



1874. Diderma marice wilsoni Clinton, Rep. N. Y. Mus., XXVI., p. 74. 



Sporangia gregarious, sessile, depressed, spherical or some- 

 times elongate, small, I mm. or less, rose white, smooth, the 

 outer peridium crustaceous, rather thick and persistent, polished, 

 slightly raised above the inner, which is dull ashen and more or 

 less wrinkled ; hypothallus none ; columella prominent, hemi- 

 spherical in the typical rounded forms, slightly rough reddish 

 or reddish alutaceous ; capillitium usually abundant, of slender, 

 delicate pale or colorless threads, little branched, and smooth ; 

 spores violaceous brown, minutely roughened, 8-9 /A. 



A very beautiful species occurring at the same time as the 

 preceding and in similar situations. All our specimens from 

 the west are on dead leaves of oak ; some eastern gatherings 

 are on moss. Easily recognized when fresh by its delicate pink 

 or roseate color ; weathered specimens are white, and might be 

 confused with forms of D. rcticulatitm, but the sporangia in 

 the present species are less flattened and only rarely in special 

 situations run off to linear or plasmodiocarpous shapes charac- 

 teristic of D. reticulatinn. 



Not common, although widely distributed from east to west. 

 New England, New York, New Jersey, South Carolina, Ohio, 

 Illinois, Iowa, Nebraska, California (Harkness). 



9. DIDERMA NIVEUM (Rostafinskt) Macbr. 



1875. Chondrioderma niveum Rost., Man., p. 170. 

 1877. Diderma albescens Phillips, Grev., V., p. 114. 



Sporangia gregarious, scattered, or more often crowded, 

 sessile, depressed, spherical, sometimes ellipsoidal or elongate, 

 white, the outer peridium crustaceous, chalky, smooth and 

 fragile, the inner distinct, delicate, ochraceous ; hypothallus 

 scant or none ; columella well developed, globose or hemispheri- 

 cal, orange tinted or ochraceous ; capillitium abundant, made up 

 of threads of two sorts, some purplish or dusky, with pale extremi- 

 ties, uneven, others more delicate and colorless, and with wart- 



