Cribraria 193 



narrow, the angles continued into the slender connecting threads, 

 or thickened and convex, often with a few free rays. Stalk sub- 

 ulate, dark brown, two to four times the height of the sporangium 

 or higher. Spores ochraceous by transmitted light, minutely 

 warted, 5-6 fx diam. 



Type locality: Germany. 



Habitat: On dead wood. 



Distribution: Common throughout the United States and 

 Canada. 



Illustration: Lister, Mycetozoa ed. 3. pi. 142. 



Lister (Mycetozoa ed. 3. 173. 1925), following Persoon, 

 recognizes C. vulgaris with paler, flattened nodes as the species, 

 and C. aurantiaca with dark, convex nodes as C. vulgaris var. 

 aurantiaca. Under present rules of nomenclature C. aurantiaca 

 must be accepted as the name, as the two forms are undoubtedly 

 the same species. Schrader distinguished the two forms on nodes 

 and color of the spores. Practically all American specimens have 

 the golden yellow color of the spores in mass. The few that are 

 paler have probably altered with age. Variation in the shape of 

 the nodes is often seen in the same development and sometimes in 

 the same sporangium. It is not considered of sufficient stability 

 to warrant a distinct variety. The color of the calyculus and 

 nodes depends much upon the number of plasmodic granules 

 present, as it does in other species of the genus. Forms with 

 thickened, convex or irregular nodes and a more regular net 

 approach C. tenella or C. intricata, but may usually be distin- 

 guished by the spore-color which is ochraceous in the species 

 named. The small size of the plasmodic granules in C. aurantiaca 

 is an important character in separating it from other forms which 

 it may resemble. 



6. Cribraria rufa (Roth) Rost. Mon. 232. 1875. 



Stemonitis rufa Roth, Tent. Fl. Germ. 1: 548. 1788. 

 Cribraria rufescens Pars. Neues Mag. Bot. 1: 91. 1794. 



Plasmodium milk-white (Lister). Sporangia scattered, 

 stalked, subglobose or turbinate, 0.5 to 0.7 mm. diam., reddish 

 orange; cup one third the height of the sporangium, with a regu- 

 larly toothed margin, more or less ribbed, the thicker ribs con- 

 tinued into the wide-meshed net; plasmodic granules^hardly 1 n 

 diam.; nodes of the net hardly expanded, or narrow, triangular 

 and flattened, connected by three or four firm threads. Stalk 



