KEY TO THE MORE IMPORTANT GENERA OF MYXOGASTRALES 37 



Fructification aethalioid, capillitium with lime knots. Fuligo 

 Fructification of plasmodiocarps or of separate sporangia. 



Capillitium of nearly uniform anastomosing tubules, containing lime 



granules throughout. Badhaniia 



Capillitium of threads containing lime knots. 

 Peridium incrusted with hme. 



Sporangium dehiscent circumscissilely. Craterium 



Sporangium by introversion thimble-like or vase-like, dehiscence 



by petal-like lobes. Physarella 



Sporangium not introverted, dehiscence irregular. Physarum 

 Peridium smooth and shining. Leocarpus 



Sporangia with lime on or in peridium, none in the capillitium. 



Family Didymiaceae 

 Calcareous deposits in form of stellate crystals. 



Aethalioid. Mucilago 



Plasmodiocarpous or of separate sporangia. Didymium 



Calcareous deposits not stellate. 



Lime in form of closely adjacent peg-like processes. Physarina 

 Lime in scattered flattened scales. Lepidoderma 



Lime forming a continuous shell, peridium mostly double. 



Diderma 

 Sporangium without lime in capillitium and peridium (in stipe and columella 

 in some species of Diachea). Capillitium of more or less reticu- 

 lately anastomosing threads. 

 Columella usually well developed, capillitium arising along its whole 

 length. Family Stemonitaceae 



Stipe and columella calcareous or waxy. Diachea 



Stipe and columella never calcareous or waxy. 



Capillitial branches forming definite outer network. Stemonitis 

 Capillitial branches not forming surface network. Comatricha 

 Columella short or well developed, capillitium arising at apex or in apical 

 portion. Family Lamprodermaceae 



Columella reaching apex of sporangium, capillitium arising from a disk 



at its top. Enerthenema 



Columella one-third to half the height of sporangium, peridium iri- 

 descent, capillitium dense, bushy, branches tapering. 



Lamproderma 

 Columella short, capillitium bushy, the tips of the branches with disk- 

 like fragments of peridium. Clastoderma 

 Spores violet to ochraceous or pale, columella and true capillitium lacking. 

 Outer layer of peridium flaking off leaving the inner layer of reticulate thick- 

 enings which surround the spore mass. 



Family Cribrariaceae 

 Meshes of the reticulum more or less isodiametric in the upper portion of 



the sporangium. Cribraria 



Thickenings of the peridium wall like the meridians on a globe with very 

 delicate cross connections. Dictydium 



Peridium wall not reticulately thickened. 



Sporangia separate, sometimes plasmodiocarpous. 



Family Liceaceae 

 Sporangia mostly sessile, not dehiscing by a lid. Licea 



Sporangia mostly stalked, opening by a lid. Orcadella 



