DiDYMIUM 119 



of rather stout, purplish brown, straight or flexuose threads, 

 equal in thickness throughout. Spores dark brownish purple, 

 13-14 n diam., marked with warts and ridges more or less united 

 to form a close reticulation. 



Type locality: Ecuador. 



Habitat: On dead leaves and herbaceous stalks. 



Distribution: *California, Colorado. 



Illustration: Lister, Mycetozoa ed. 3. pi. 218, figs. f-h. 



Allied to D. difforme, from which it differs in the dark net- 

 work of the capillitium and in the uniformly dark spores being 

 marked with an imperfect reticulation. 



3. Didymium trachysporum G. Lister, Essex Nat. 20: 113. 

 1923. (N. Y. B. G. no. 8963, authentic material.) 



Plasmodium colorless (Lister). Sporangia more or less scat- 

 tered, hemispherical, 0.2 to 0.6 mm. diam., or forming slender, 

 simple, curved, branched or ring-shaped plasmodiocarps, white 

 or cream-colored; outer sporangial wall a smooth or wrinkled 

 crust of closely compacted lime-granules, the inner one mem- 

 branous, colorless. Floor of sporangium pale yellow, mem- 

 branous with a thickened margin, and with scanty, rarely 

 abundant, deposits of lime-crystals. Capillitium rather scanty, 

 variable, consisting usually of a network of colorless or purplish, 

 stout or slender threads, sometimes with vesicular expansions 

 enclosing lime-crystals. Spores brownish purple, 9-10 )u diam., 

 marked with short spines, scattered or grouped in clusters, rarely 

 with patches of broken reticulation; spores often traversed by a 

 low ridge. 



Type locality: England. 



Habitat: On dead leaves and herbaceous stalks. 



Distribution: *Oregon. 



Illustration: Lister, Mycetozoa ed. 3. pi. 218, figs. a-e. 



Also related to D. difforme and similar in appearance, but 

 differing in the spore-characters. The species is not rare in 

 Europe. 



4. Didymium Listen Massee, Mon. 244. 1892. 



Didymium duhitim Rost.; Lister, Mycetozoa 95, in part. 1894, (N. Y. B. G. 

 nos. 13082, 13083, Lister material.) 



Plasmodium watery white (Lister). Sporangia solitary, hemi- 

 spherical, flattened, 0.5 to 1 mm. diam., or forming broad. 



