36 



MYXOMYCETES. 



II. Columella usually snow-white, rarely 

 straw or flesh-coloured, with similar 

 stem. 



j- Wall of sporangium double . 

 j-j Wall of sporangium single. 

 * Sporangium sessile. 



Spores very spinulose, large ; 

 columella usually coloured ; 

 capillitiurn fasciculate 

 Spores almost smooth, smaller ; 

 columella usually snow- 

 white ; capillitium combined 

 into a net 



Sporangium stipitate. 

 ! Columella globose. 

 Lower wall of sporangium fit- 

 ing close to the smooth 

 columella ; capillitium of 

 simple threads . 

 Lower wall of sporangium not 

 close to the convex colu- 

 mella, which has numerous 

 rough projections from which 

 rise bundles of the threads of 

 the capillitium . 

 ! Columella discoid, or arcuate 

 at the edge, and bent down- 

 wards ; capillitium without 

 colour .... 

 Capillitium coloured brown . 



prcecox. 



confluens. 



effuswn. 



SQUAMDLOSUM. 



FucTcelianwn. 



macrospermum. 

 discoideum. 



Genus 13. 



CHONDRIODERMA. Ittflti. 



Peridium sessile or stipitate, splitting irregularly, or in a 

 stellate manner ; wall of peridium single or double ; outer wall 

 covered with shapeless granules of lime, or crustaceous by their 

 accumulation, separated from the inner one (when present) by a 

 considerable space filled with air ; inner wall delicate, containing 

 no lime, iridescent ; columella usually present. Rtfki. Mon., p. 167. 



Sub -Genus 1. Monoderma. 



Wall of sporangium single, covered on the outside with granules 

 of lime in one stratum. 



This sub genus includes 



Ch. Alexandrowiczii. 



Ch. pezizoides. 



Ch. injiatwn. 



Ch. reticulatum. 

 None of which are British. 



