4 



MYXOMYCETES. 



ANALYTICAL KEY 

 FOR THE DETERMINATION OF THE GENERA. 



1. Spores outside the sporangium or sethalium 



(Exosporce) ...... 



Spores inside the sporangium or gethalium 

 (JEndosporce) ...... 



2. Sporangia grown together into a dendritic or 



branched form, or into a net with polygonal 

 openings ...... 



3. Spores violet, or brownish-violet colour (Am- 



aurosporce) ...... 



Spores otherwise coloured, mostly of bright 

 colour (Lamprosporce) . . . . 



4. Without capillitinm (Atrichce) 

 With capillitinm ( Trichophorce} . 



5. Sporangium single (Protodermecs) 



6. Wall of sporangium single 



7. Deposits of lime on the surface, or outside 



the sporangium or sethalium (Calcarece) 



Sporangium or aethalinm without deposits 



of lime (AmaurochetfCB^ .... 



8. Capillitium of coloured threads combined 



into a network, some of the branches with 

 free extremities (Cienkowskiacece) . 

 Capillitinm of thin-walled, colourless, trans- 

 lucent tubes, usuallv combined into an 



/ / 



irregular network, expanded and wider at 

 the angles, not usually developed into, or 

 replaced by, a central knot, or " columella" 

 (Physaraceoi) ..... 



Capillitium of very thin threads, or more 

 rarely of sparse tubes, usually violet, or 

 more rarely colourless, simple, or combined 

 by transverse branches into a network, with- 

 out deposits of lime. Columella usually 

 strongly developed (Didt/mia<-ea>) 



Sporangium cylindrical, ol tuse, simple or 

 combined into tree-like branches. ^Etha- 

 lium also cylindrical, with a central colu- 

 mella. Capillitium of violet threads with- 

 out lime, combined into a network (Spu- 

 mariacece] ..... 



9. Free ends of capillitinm attenuated, grains 



of lime very strongly developed, and usually 

 branched ...... 



10. Sporangium single ..... 



Sporangia combined into an entangled phiit 

 (gethalium) ...... 



2 

 3 



Ceratium. 

 4 



32 



5 



7 

 6 

 Protoderma. 



8 

 21 



9 



10 



19 



20 



Cienkowskia. 

 11 



Fid i (jo. 



