iS 



Cincinnati Society of Natural History. 



3. Physarum obrusseum, B. &. C. Sporangium globose, 

 the base usually slightly flattened or umbilicate, stipitate and 

 cernuous; the wall a thin, violaceous membrane, covered by 

 small, roundish, white or yellow scales of lime, or sometimes 

 naked, splitting irregularly from the apex downward. Stipe 

 long, slender, tapering upward, flexuous, bent or curved at 

 the apex, yellow, yellow-brown, or pale brown. Capillitium 

 of very slender tubules, forming a loose net-work, scarcely 

 expanded at the angles ; the nodules of lime small, white or 

 yellow, roundish or obtusely angular, few to numerous, rarely 

 wanting. Spores globose, very minutely warted, violaceous, 

 8-10 mic. in diameter. 



Growing on old wood, bark, mosses, etc. Sporangium .2-4 

 mm. in diameter, the stipe 1-2 mm. in length, the lime 

 nodules when abundant once to twice the diameter of the 

 spores, when scanty very small. This, as I find it growing, 

 is an extremely variable species ; I think its various forms 

 and appearances cover such species as Didymium obrusseum 

 B. & C; D. tenerrimum B. & C; Physarum tenermn Rex, 

 etc., etc. 



4. Physarum nuclkatum Rex. Sporangium globose, 

 stipitate, erect or slightly nodding ; the wall a thin, pellucid 

 membrane, thickly covered with minute, white, roundish 

 scales of lime, which are exceptionally sparse or absent, rup- 

 turing irregularly. Stipe long, slender, yellowish-white, 

 longitudinally rugulose, tapering upward, expanded at the 

 base into a small hypothallus. Capillitium of very slender 

 tubules, forming a delicate net-work of small meshes, scarcely 

 expanded at the angles ; nodules of lime small, not numer- 

 ous, roundish, white, usually concentrated into a large lump 

 in the center of the sporangium. Spores globose, very 

 minutely warted, violaceous, 6-7 mic. in diameter. 



Growing on old wood, bark, etc.; rare. Sporangium .4-. 5 

 mm. in diameter, the stipe two or three times as long, the 

 lime-nodules about the size of the spores. The species much 

 resembles some of the forms of P. obrusseum, but is to be 

 distinguished by its central mass of lime and the small spores. 



5. Physarum compactum Wingate. Sporangium de- 

 pressed-globose, the base slightly umbilicate, stipitate, cernu- 



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