226 Mycetozoa of North America 



Distribution: Common and abundant in the United States 

 and Canada; not so common in the tropics. 



Illustration: Lister, Mycetozoa ed. 3. pi. 159, figs, a, h. 



Rarely, the sporangia have membranous stalks which may be 

 up to 0.3 mm. high. They must not be confused with T. verru- 

 cosa as they have the sporangial walls, elaters, and spores of 

 T. favoginea. This species, and the three following ones, consti- 

 tute a group of related forms which are connected by many inter- 

 mediates. Abnormal developments may have branched elaters 

 or a netted capillitium like in the genus Hemitrichia. In cold 

 weather developments, the spirals on the elaters may be replaced 

 partially by rings. The descriptions apply therefore to the 

 various centers around which the connecting forms are grouped, 

 and which are usually constant in normal developments. The 

 markings on the sporangial wall, the breadth of the elaters, and 

 the height, pitting, and number of bands on the spores are im- 

 portant characters which must not be overlooked in separating 

 the species. 



2. Trichia verrucosa Berk, in Hooker f., Fl. Tasm. 2 : 269. 1859. 

 Trichia superba Massee, Jour. Roy. Micr. Soc. 1889: 345. 1889. 



Plasmodium white (Lister). Total height 2 to 4 mm. Spo- 

 rangia stalked, rarely sessile, piriform or clavate, clustered or soli- 

 tary, L4 mm. high, 0.8 mm. broad, ochraceous yellow; mass of 

 elaters and spores golden yellow; sporangial wall membranous, 

 minutely and closely papillose on the inner side, pale yellow, 

 sometimes with an outer layer thickened by granular deposits. 

 Stalks membranous, 1 to 2 mm. high, usually combined in clusters 

 of three or four, rugose, yellowish brown or dark brown. Capil- 

 litium of long cylindrical elaters 4-6 ju wide, with short, conical 

 ends, marked with three to five narrow spiral bands, smooth or 

 with a few scattered spines; longitudinal striae distinct. Spores 

 reticulate, with narrow, minutely pitted bands forming a network 

 with about seven meshes to the hemisphere, 13-16 /i diam.; 

 border 1 n wide. 



Type locality : Tasmania. 



Habitat: On dead wood. 



Distribution: *Dominica, *Mexico, ^Washington. 



Illustration: Lister, Mycetozoa ed. 3. pi. 161, figs, a, b. 



