38 MTCETOZOA AND RELATED ORGANISMS 



Sporangia closely appressed, retaining their walls, dehiscent at apex. 



Family Tubiferaceae 

 Sporangia cylindrical, densely clustered. Tubifera 



Sporangia ovate in a loose cluster on a common stalk. 



Alwisia 

 Sporangia sessile, flattened, closely clustered into a pseudoaethalium, 

 rarely scattered. Liceopsis 



Forming an aethalium, no sporangial walls remaining at maturity. 



Pseudocapillitium thread-like or of perforate or frayed sheets, spores 

 ochraceous. Family Reticulariaceae 



Surface alveolar, made up of the caps of the sporangial units. 



Dictydiaethalium 



Surface not alveolar. 



Pseudocapillitium of flat irregular plates fraying out into threads. 



Reticularia 

 Pseudocapillitium of broad perforated plates. Enteridium 

 Pseudocapillitium of colorless branched tubes, spores pale. 



Family Lycogalaceae 

 Only genus. Lycogala 



Spores yellow to ochraceous, capillitial threads with characteristic markings: 

 spirals, rings, spines, cogs, etc., sometimes faint or wanting. 

 Capillitium a network or of separate threads, marked with spiral bands, 

 threads coarse. Family Trichiaceae 



Capillitial threads separate, spirals irregular or faint. Oligonema 

 Capillitial threads separate, spirals distinct, regular. Trichia 



Capillitial threads forming a network. 

 Spirals regular. Hemitrichia 



Spirals irregular or obscured by reticulations. Calonema 



CapilUtium a network of coarse threads attached to lower part of peridium, 

 markings various, never of spirals. Family Arcyriaceae 

 Capillitium elastic, pushing out far beyond the cup-like base of the 



peridium. Arajria 



Capillitium not elastic. Lachnobolus 



CapiUitial threads slender, warted or spinulose or smooth. 

 Capillitial threads soUd, peridium usually single. 



Family Dianemaceae 



Capillitial threads hair-like, coiled. Margarita 



Capillitial threads nearly straight. Dianerm 



Capillitial threads hollow, peridium double. Family Perichaenaceae 

 Capillitium warty or spiny, dehiscence irregular. Ophiotheca 



Capillitium as above, dehiscence circumscissile. Perichaena 



Key to the Genera of Order Acrasiales 



Myxamoebae with inconspicuous, rounded pseudopodia. 



Fruiting bodies sessile. Copromyxa 



Fruiting bodies short-stalked. Guttulina 



Myxamoebae with well-developed, more or less acute, pseudopodia. Fruiting 

 bodies stalked. 

 Spores in rounded slime-covered heads. 



Stalks not branched. Didyostelium 



Stalks branched. Pohjsphondylium 



Spores in chains, stalks not branched. Acrasis 



