44 A Monograjyh of the Mi/xogastres. 



black; spores globose, IG — 18// diameter; episporc blackish 

 violet, smooth. 



Protoderma ]p%silla, Host., Mon., p. 90. 



Protodermiwm imsillum, Sacc, Syll., Vol. vii., pt. I, n. 1139. 



On rotten wood. Germany; Russia; United Status. 



(Rostafinski's Synonyms.) 

 Zicea pusilla, Sclirad., Nov. Gen., p. 19, t. vi., f. 4 (1797). 

 Pliysarum licea, Fr., S. M., iii., p. 143 (1829). 



Sub-sect. Cribrariae. 

 Enteridium, Rost. (emended). 



Aethalium covered with a general, irregularly perforated, 

 membranaceous cortex ; walls of component sporangia with 

 symmetrical perforations, or irregularly broken up to form a 

 capillitium-like structure. 



Rost., Mon., IX 226; Cooke, Myx. Brit., p. .56; Schroeter, 

 p. 103; Sacc, Syll, Vol. vii., pt. I., p. 409. 



Very closely allied to the CkctliroptijcMum, which differs 

 chiefly in the more complete absorption of the walls of the 

 sporangia. 



In E. olivacenm, which most nearly approaches CJatliropty- 

 chiitm in structure, the side walls of the sporangia are not so 

 completely absorbed as in the last-named genus, hence the 

 thickened angles formed by the walls of contiguous cells have 

 broader and more irregular wings. 



Distrih. Europe ; United States ; W. Australia : species 3. 



A. Spores Beticulatcd. 

 E)ifcridii(m olivacctt.m,'Rost. (f. 14 — 18). 

 Aethalium very variable in form, flattened or pulvinate, olive ; 

 general cortex papery, pellucid ; walls of the crowded sporangia 

 pellucid, yellowish-brown, perforated; mass of spores olive; 

 spores in clusters of from 5 — 20, single sjwrcs truncate, the free 

 portion convex ami wartcd, rcmaini^ig 2'>ortion smooth, 11 — 15 /x 

 diameter. 



