234 A Monograph of the Myxogastres. 



stem, wall dark grey, at first with granules of lime ; columella 

 irregular, more or less confluent and common to all the sporangia ; 

 threads of capillitium 2 3 \J. thick at base, with but few 

 bifurcations, with numerous fusiform or discoid dingy purple 

 thickenings, spores globose, brownish purple, ivartcd, 12 14 /* 

 diameter. 



Didymium physarioides, Host, Mon., p. 158, fig. 147 ; Cooke, 

 Myx. Brit, p. 33, f. 147 ; Sacc., Syll., no. 1311. 



On nioss and wood. Britain (King's Cliffe, Carlisle); Ger- 

 many ; Sweden ; United States ; Cape of Good Hope. 



Often superficially resembling Physarum didermoidcs. 



Didymium serpula, Fr. (figs. 5557)1- 



Sporangia sessile on a broad base, much adpressed, circular in 

 outline, or variously elongated and flexuous, and sometimes the 

 branches combine to form an irregular network, wall dark grey, 

 sparingly sprinkled with minute white particles of lime ; columella 

 absenj^ mass of spores blackish ; threads of capillitium branched 

 and connected laterally, forming an irregular network, dirty 

 brown to colourless, plentifully furnished with dark- coloured, 

 ring-like, or irregularly-shaped thickenings; spores globose, 

 very minutely verruculose, 79 p diameter. 



Didymium serpula, Rost., Mon. Append. ; Cooke, Hdbk., 30, 

 figs. 166, 180; Schroeter, p. 121 ; Sacc., Syll., no. 1297. 



Didymium complanatum, Rost., Mon., p. 151, figs. 166, 180. 



On leaves, &c. Sporangia when circular "5 1 mm. diameter ; 

 when elongated often several mm. in length. Sometimes the 

 lime on the sporangium is more abundant, forming a white 

 crust ; but the species cannot be mistaken if attention is paid 

 to the much flattened sporangia, the well-developed capitulum 

 having the threads furnished with numerous, variously-shaped, 

 dark brown thickenings, and the very minutely verruculose 

 spores. 



Britain (Kew, Batheaston, Scarboro', Carlisle); all Europe; 

 United States. 



