184 THE JOURNAL OF BOTANY 



7. Gienkowskia Rostafinski. Sporangium-wall cartilaginous at 



the base ; capillitium a loose network of rigid threads with 

 many free curved, sharp-pointed branchlets, connected with 

 flat perforated calcareous plates attached at their margins to 

 the sporangium-wall C. reticulata Rost. 



8. Fuligo Haller. Sporangia elongate, branching and interwoven, 



forming a pulvinate aethalium, often with a barren superficial 

 layer forming a cortex ; capillitium as in Physarum. 



iEthalium and lime-knots yellow, rarely reddish or white ; spores 

 7-8 /x F. septica Gmel. 



jEthaliuHi yellowish grey, lime-knots numerous, orange-yellow ; 

 spores 10-11 /x . . F. muscorum A. & S. (1, p. 240"). 



(syn. F. ochracea Peck). 



iEthalium and lime-knots pure white, the latter large ; spores 

 usually ellipsoid, J 3 x 16 //. . . . F. ellipsospora List. 



9. Craterium Trent. Sporangium stipitate, goblet-shaped, usually 



with a lid of thinner substance, or ovoid or globose ; sporangium- 

 wall charged with lime and cartilaginous at least in the lower 

 part ; stalk cartilaginous, translucent ; capillitium of branch- 

 ing hyaline threads connecting large lime-knots which are 

 often confluent in the centre, forming a pseudo-columella. 



Sporangium- wall smooth, glossy — 



A. 



pedunculatum 



b. Sporangium- wall mealy or rugose 



concinnum 



w v o - — 



Sporangia violet C. rubescens Rex 



Sporangia brown, powdered with white in the upper part 



C. leucocephalum Difcm. 

 Sporangia yellow rugose — 



a. Sporangia ovoid, spores 7-9 /x . . C. mutabile Fi\ 



b. Sporangia globose, spores 10-12 [m 



!. citrinellum List. 



10. Leocarpus Link. Sporangium-wall of two layers, the outer 



cartilaginous and calcareous, the inner hyaline; capillitium 

 a network of hyaline threads with branched and anastomosing 

 brownish lime- knots L. vernicosus Link 



11. Chondrioderma Eost. Sporangium-wall charged with lime 



in the form of round granules (except in 6\ Trevelyani q. v.) ; 

 capillitium without lime-knots. 



Subgenus 1. Euchondrioderma. Outer sporangium- wall a 

 smooth crust composed of lime granules densely compacted 

 (except in C simplex); inner layer membranous. 



a. Spores reticulated . . . C. subdictyospermum Rost. 



b. Spores not reticulated — 

 a. Sporangia white — 



Sporangia disc-shaped, stalked , ♦ C. Michelii Rost. 



