Cincinnati Society of Natural History. 



B. Sporangia sessile. 



ri. Physarum confIvUKns Pers. Plasmodiocarp roundish, 

 oblong or elongated, and by confluence branched and reticu- 

 late ; the wall a thin, violaceous membrane, rugulose, with 

 a thin, closely adherent layer of minute granules of lime, 

 over which are scattered small, white, roundish nodules, 

 which sometimes accumulate into a thick, pulverulent coat. 

 Capillitium a loose net-work of tubules, widely expanded at 

 the angles ; the nodules of lime small, white, very numerous, 

 roundish or ellipsoidal, by confluence elongated and irregular. 

 Spores irregularly globose, minutely warted, dark violaceous, 

 9-1 1 mic. in diameter. 



Growing on old wood, bark, leaves, etc. Plasmodiocarp 

 .4-. 5 mm. in thickness, varying from roundish to much 

 elongated, creeping and reticulate. The sporangium before 

 dehiscence is gray, whence Link's name, Physarum griseum; 

 the loose pulverulent coating of lime easily falls away, leav- 

 ing the sporangium dark colored, whence Rostafinski's name, 

 Physarum lividum. The amount of lime on the wall and in 

 the capillitium is variable. 



12. Physarum luteolum Peck. Sporangia small, sub- 

 globose, sessile, closely gregarious ; the wall a thin mem- 

 brane, covered by a layer of small scales of lime, yellowish, 

 inclining to tawny, in color, rupturing irregularly. Capil- 

 litium of slender tubules, forming a dense net-work of small 

 meshes, scarcely expanded at the angles ; the nodules of lime 

 small, numerous, yellowish, roundish, or ellipsoidal. Spores 

 globose, nearly smooth, violaceous, about 10 mic. in diameter. 



Growing on living leaves of Corjius canadensis, Adiron- 

 dack Mountains, New York. I have not seen a specimen of 

 this Physarum, but from Professor Peck's description and 

 figure it seems to be a unique species. 



13. Physarum thejoteum Fr. Sporangia very small, 

 sessile, on a thin membranaceous hypothallus, closely crowded 

 together and more or less connate, subobovoid or oblong, 

 irregular from mutual pressure ; the wall a thin violaceous 

 membrane, closely covered with a thin layer of small irregu- 

 lar scales of lime, tawny or yellowish tawny in color, break- 

 ing up irregularly about the apex. Capillitium a loose irregu- 



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