The Myxomycetes of Eastern Iowa. 147 



spores are minutely verruculose and larger than the size 

 quoted would indicate, .00S-.009. Rare, on fallen sticks, 

 leaves, etc., in the fall, Decorah. Mr. Holway. 



CHONDRIODERMA, Rostafinski. 



Sporangia distinct or plasmodiocarpous, sessile or stalked. 

 Peridium usually double, the outer wall charged with amor- 

 phous granules of lime or crust-like by their accumulation, 

 splitting irregularly or stellately to reveal the remote, delicate, 

 iridescent, lime-free inner wall. Columella usually present and 

 well developed. 



46. Chondrioderma globosu-M, Persoon. Plate VII, Figs. 

 5, 5^ and 7. 



Sporangia spherical or globose, attached by a narrowed 

 base to the substratum, or resting upon a strongly developed 

 hypothallus, white with lime. Outer peridium lime -white, 

 brittle, the inner gray or iridescent. Columella usually very 

 small, globoidal or ellipsoidal, snow-white as the hypothallus. 

 Capillitium violet-tinted, made up of anastomosing threads; 

 spores of the same color, minutely rough, .008. 



The Chondriodermas are generally delicately beautiful. 

 The outer wall in the present species is like finest unglazed 

 china, softly smooth and yet not polished, absolutely white, 

 with porcelanous fracture. An inter-parietal space separates 

 the outer from the inner wall, so that the former may be 

 broken, bit by bit, without in the least disturbing the under- 

 lying structure. The inner wall is ashen or gauz}- iridescent 

 green, sending back all colors in reflected light. The spores 

 are violet, deeply so when fresh, the capillitium strong and 

 likewise tinted, the columella passing down and blending 

 with the common snow-white hypothalline base. Tw^o dis- 

 tinct habits present themselves, represented in Figs. 5 and 7. 

 In the one the distinct sporangia are associated but not 



