The Myxomycetes of the Miami Valley, Ohio. 



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several to many laterally compressed, irregular, simple spo- 

 rangia ; the wall a thin, pellucid membrane, covered by a thin 

 la}'er of minute scales of lime, white to yellow or greenish- 

 yellow. Stipes thin, flat, weak, and often prostrate, pale 

 yellow, more or less connate, arising from a thin hypothallus. 

 Capillitium of slender tubules forming a loose, irregular net- 

 work, more or less expanded at the angles : the lime-nodules 

 white or yellow, small, fusiform or by confluence elongated 

 and sometimes branched. Spores globose, very minutely 

 warted, violaceous, 8-10 mic. in diameter. 



Growing on old bark, wood, leaves, etc. The sporangia 

 rarely simple, usually confluent into a head of from four or 

 five to fifteen or twenty, and sometimes more, simple spo- 

 rangia ; the stipes variable in length, long or short, rarely 

 wanting. The gray form is Didymium polyjnorphum Mont., 

 the yellow-green form D. gyrocephalum Mont. Sprengel con- 

 sidered this species the same as Physarum compactum Khr., 

 and it appears under this name in Schweinitz's North Amer- 

 ican Fungi; but Fries, who had seen specimens of both, dis- 

 posed of them differently. 



10. Physarum didermoides Pers. Sporangia obovoid- 

 oblong, stipitate, growing close together on a white membran- 

 aceous common hypothallus ; the wall with a thick, white, 

 outer layer of lime, easily crumbling and falling away, leav- 

 ing the sporangium dark gray ; the inner membrane rather 

 thick and firm, violaceous, with a closely adherent layer of 

 granules of lime. Stipes very short, white, thin, and weak, 

 each formed by a bit of membrane arising from the hypo- 

 thallus. Capillitium a loose net-work of slender threads, bear- 

 ing numerous roundish or irregular white nodules of lime. 

 Spores irregularly or angularly globose, minutely warted, dark 

 violaceous, 12-15 m ic- in diameter. 



Growing on wood, leaves, grass, etc. Sporangia .6-1.2 mm. 

 in length by .4-. 6 mm. in thickness, the stipe shorter than 

 the sporangia. Spumaria licheniformis Schw., belongs here. 

 This is a truly abnormal species of Physarum, so much so 

 that Fries, in the Summa Veg. Scand. placed it by itself in a 

 separate genus, Claustria. 



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