Didymmm. 243 



more especially so when dealing with diagnoses of microscopic 

 species described half a century ago. The following synonyms 

 by Rostatiuski, although absolutely worthless from a scientific 

 standpoint, may be historically interesting. 



(Rostafinski's Synonyms.) 

 Physarum Jiavicomum, B., Hook. Journ., p. QQ, n, 63 (1845), 

 Stylonitcs fulviceps, Fr., Fung. Natal, p. 33 (1848). 

 Physarum mjjriceps, B. et Rav., Fung. Car. Exs. iii., n. 76 

 (1855). 



Ophiotheca ? Roussel. Antil. (1872). 



Physarum cuprijjes, B. and Rav., Grev., p. 65, n. 355 (1873). 

 Physantm rosetcm, B. et Br., cfr. Grev., p. 65 (1873). 



Didymium elegantissimum, Mass. (n. sp.). 



Sporangia scattered, stipitate, hemispherico-depressed, with a 

 broad, shallow umbilicus below, smw- white, with a dense coat- 

 ing of stellate crystals; stem elongated, equal, rather stout, 

 longitudinally rugulose, bright orange-hroivn, passing into a small 

 hypothallus of the same colour; capillitium absent; threads 

 3 — 4 /^ thick at the base, forking at acute angles, here and 

 there anastomosing to form irregular portions of network, most 

 of the main branches with numerous small nodulose siuellings at 

 regular intervals, giving a moniliform appearance, pale and 

 lilac-brown below; spores globose, 8 — 10 /x diameter, mwrni^gZy 

 vMrtccl, pale lilac. 



Physarum striatum, Fr., Syd. Myc. March., 490 (Kew copy). 



On twigs and leaves. Britain (Scarboro') ; Germany. 



About 1-5 mm. high. Stem two or three times as long as 

 sporangium. Bears a superficial resemblance to Didymium 

 p>crtusum, Berk., from which it is readily distinguished by the 

 denser capillitium aud the moniliform thickening of the threads. 



B. Spoi'angimii sessile. 

 Didymium leptotrichum, Mass. 

 Sporangia venulose or irregular, depressed, wall single. 



