2S 



Cincinnati Society of Natural History. 



and occasionally forming a pseudo-columella in the center of 

 the sporangium. Spores globose, minutely warted, dark 

 violaceous, 10-13 m i c - i n diameter. 



Growing on old wood, leaves, etc. The sporangia .4-6 

 mm. in diameter, more or less irregular. The great abund- 

 ance of lime in the capillitium and the large distinctly warted 

 spores distinguish this species. Physarum cinereum of Per- 

 soon's Synopsis, Didymium cinereum of Fries' Sysiema. The 

 only American specimens I have of this species are from 

 Iowa (Mc Bride) and from Nebraska (Webber). 



25. Physarum virkscens Ditm. Sporangia large, sub- 

 globose, irregular and unequal, sessile, gregarious, sometimes 

 crowded, but not often confluent ; the wall a thin membrane, 

 violaceous, or in places yellowish, with a dense layer of 

 yellow or greenish - yellow scales and granules of lime. 

 Capillitium a loose net-work of tubules, with wide expansions 

 at the angles ; the nodules of lime large, numerous, yellow or 

 greenish-yellow, more or less elongated, lobed, and branched. 

 Spores globose or somewhat irregular, very minutely warted, 

 violaceous, 9-1 1 mic. in diameter. 



Growing on old leaves, mosses, etc. Sporangia .5-8 mm. 

 in diameter, occasionally by confluence more elongated. 

 Though found in all parts of the country, the species seems 

 rare. This is not the Physarum virescens described by Rosta- 

 finski. 



26. Physarum rubiginosum Fr. Sporangia subglobose, 

 sessile, gregarious; the wall a thin hyaline membrane, thickly 

 covered with large irregular scales of lime, orange to red or 

 dark red in color, breaking up irregularly. Capillitium of 

 hyaline tubules, forming a loose irregular net-work, more or 

 less expanded at the angles; the nodules of lime large, angu- 

 lar, and irregular, sometimes confluent, orange to dark red in 

 color. Spores globose, very minutely warted, dark violaceous, 

 9-1 1 mic. in diameter. 



Growing on old wood, leaves, mosses, etc. Sporangia .6-.8 

 mm. in diameter. Physarum fulvum Fries S. M., Ill, p. 143. 

 A rare species. It should not be confounded with Physarum 

 later itium. 



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