The !\fyxomycefes of the Miami Valley, Ohio. 147 



A. Spora>i^ini!i stipitate. 



iS. DinvMirM FARiNACivUM, Schrad. vSporangiuin hemis- 

 pherical, more or less depressed, the base profoundly umbili- 

 cate; the wall firm, rugulose, dark-colored and nearl}' opaque, 

 with a mealy coat of stellate crystals of lime, rupturing irreg- 

 ularly. Stipe variable in length, rigid, erect, black or some- 

 times rusty-brown, arising from a small hypothallus; the 

 columella broad, hemispherical or pulvinate, black, the lower 

 side connate with the wall of the sporangium. Capillitium of 

 dark-colored sinuous threads, simple or scarcely branched. 

 Spores globose, dark violaceous, minutely warted, 10-13 rnic. 

 in diameter. Plate XII, Fig. 40. 



Growing on old wood, leaves, mosses, etc. Sporangium 

 .6-.9 mm. in diameter, the stipe about as long as the diameter 

 of the sporangium or sometimes much longer, usually, how- 

 ever, much shorter than the diameter and almost concealed 

 within the umbilicus. My specimens are from Pennsylvania 

 and Alabama. It is readily distinguished from Didymium 

 minus by the much larger and more distinctly warted spores. 



9. Didymium clavus, A. & S. Sporangium pileate, very 

 much depressed, convex above and concave below, stipitate ; 

 the wall a dark-colored membrane, thickly covered with 

 minute white crystals of lime, except the brown concavity 

 underneath, the upper part breaking away, the lower persistent. 

 Stipe short, erect, rugulose, brown or blackish, expanding at 

 the base into a small hypothallus ; the columella reduced to a 

 thin layer of minute brown scales upon the base of the 

 sporangium. Capillitium of simple or sparingly-branched 

 threads, colorless at the extremities and dark-colored between. 

 Spores globose, even, violaceous, 6-8 mic. in diameter. 



Growing on old leaves, sticks, herbaceous stems, etc. The 

 sporangium .6-.8 mm. in diameter, the stipe about the same 

 length. Fries considered this to be a mere variety of D. 

 farinaceimi, but it is readily distinguished by its very small 

 spores. 



B. Sporangia sessile. 



10. Didymium vSERpula, Fr. Plasmodium yellow. Plas- 

 modiocarp much depressed, subrotund or usually more or less 



