60 THE MYXOMYCETES 



diderma, but a craterium (Lister) or physarum (Massee). There 

 seems no reason why we should not respect the decision of Massee, 

 whose description is here quoted in somewhat abridged form. The 

 peridium is about as double as in many physarums, not more so; 

 the inner membrane so delicate as only occasionally to be revealed 

 except to searching scrutiny. But the appearance as a whole is as 

 of some brown diderma; only the calcareous capillitium abides to 

 prevent mistaken reference. 



When opened by irregular dehiscence from above, the persisting 

 cup-like base of the sporangium recalls Leocarpus fragilis; but then 

 again the capillitium is different. 



Rare but widely distributed. Colorado, Montana, California, Chile; 

 Europe, Australia. 



26. Physarum ,eneum (List.) R. E. Fries 



Arkiv Bot. 1 : 62. 1903. 



Sporangia sessile, subglobose or forming simple plasmodiocarps 

 0.3-0.4 mm. in diameter, pinkish brown or bronze, glossy; peridium 

 double, the outer somewhat cartilaginous, brittle, falling back from 

 the shining, membranous inner wall; capillitium dense, the nodules 

 not large, brown, sometimes aggregated to form a pseudocolumella ; 

 spores pale brownish violet, nearly smooth, 6-8 /a. 



Reported from West Indies, Bolivia; India. 



27. Physarum bogoriense Racib. 



Hedwigia 37 : 52. 1898. 



1873. Diderma pallidum Berk. & Curt., Grev. 2 : 52, without description. 

 1898. Physarum pallidum (B. & C.) Lister, Jour. Bot. 36 : 117. 



Sporangia sessile, subglobose, oval or forming elongate but not 

 reticulate plasmodiocarps, semicircular in transverse section; peridium 

 double, the outer thick, smooth, yellow or brown on the outside, white 

 inside, dehiscing in stellate fashion into persistent, more or less tri- 

 angular, reflexed lobes, remote from the thin, colorless or somewhat 

 iridescent inner wall; capillitium consisting of numerous large white 

 smooth-walled rounded and branching lime-knots connected by slender 

 hyaline threads; spores bright violet, "nearly smooth" or covered 

 with rather coarse warts, 7.5-8.5 /*, sometimes up to 10 p. 



A distinct species, marked by its diderma-like, brown, distant outer 

 coat, with lobed or stellate dehiscence, and semicircular or somewhat 



