76 THE NORTH AMERICAN SLIME-MOULDS 



nothing of the stouter, larger, in every way coarser forms called by 

 Rostafinski P. nefroideum, P. compressum, P. lividum, etc. 



The shadowy little species has had an eventful history, dipping in 

 and out of our story in most uncertain fashion. Beginning with 

 Fries, as noted, it received confirmation at the hands of DeBary, 

 and by Rostafinski was given priority over a long list of synonyms, 

 and figured. The earlier English authors follow Rostafinski, but 

 for Lister in the Mycetozoa, p. 51, the species becomes a synonym of 

 T. alba as P. nutans, the description appropriately enlarged to receive 

 it. Meantime American students generally confused it with the 

 tilmadoches on the one hand and P. nefroideum R. (supposed) on the 

 other. In 1897, Robt. Fries in Sver. Myxom. Flora, brings the 

 species again to view as co-partner with P. nutans and in the Mycet- 

 ozoa, 2nd ed., p. 67, it appears as sub-species to the same. 



The resemblance to P. album or P. nutans, is chiefly as intimated, 

 a matter of definition ; real differences are found in the irregular cap- 

 illitium, fitting a globose sporange, in the character of the stipe and 

 the consequent pose. See under P. nutans and P. notabile. 



34. Physarum nodulosum Cke. ^ Balf. 



1881. Physarum nodulosum Cke. & Balf., Ra<v. N. A. F., Exsic, 479. 



1889. Badhamia nodulosa Massee, Jour. Myc, Vol. V., p. 186. 



1891. Physarum calidris Lister, Jour. Bot., Vol. XXIX., p. 258. 



1896. Crater'tum nodulosum (Cke. & Balf.) Morg., Jour. Cin. Soc, p. 87. 



1899. Physarum nodulosum Cke. & Balf., Macbr., A^, A. S., p. 51. 



1911. Physarum pusillum List., Mycetozoa, 2nd ed., p. 64. 



Sporangia gregarious ; minute, globose, bluish-white, the sporangia! 

 wall thin and more or less encrusted with lime, breaking up ir- 

 regularly, stipitate ; stipe slender, longer than the sporangium, attenu- 

 ate upward or even, bright brown, rugose, expanded above into a 

 shallow cup-like base for the sporangium ; columella none ; capillitium 

 with lime-knots more or less abundant, white, often uniting, bad- 

 hamioid; spore-mass black; spores by transmitted light, pale lilac- 

 brown, almost smooth, 10-12 ju. 



Pennsylvania, Ohio, Iowa; Canada. 



One of the smallest species of the genus, by its proportionally long 

 stipe and small round sporangium reminding one somewhat of P. 



