250 Mycetozoa of North America 



lation or occasionally with three or four faint, irregular, spiral 

 lines; basal threads smoother and attached to the cup. Spores 

 6-8 /x diam., nearly smooth. 



Type locality: England. 



Habitat: On dead wood. 



Distribution: New York, Pennsylvania, Quebec. 



Illustration: G. Lister, Jour. Bot. 59: pi. 558, figs. 2, 2a, 2b. 



This species is not clearly marked with sufficient definite 

 characters, and I doubt if anybody can understand it except the 

 author. Miss Lister says in the original description that it may 

 resemble in the field the robust forms oi A. insignis. Three such 

 specimens from the states reported have the capillitium firmly 

 attached to the cup. The threads are broader than those of 

 A. insignis and are marked with cogs or square-ended promi- 

 nences. They are regarded as A. carnea, but similar markings 

 are often seen in A. denudata or A. incarnata. Forms exactly 

 like those regarded as A. carnea, except that the capillitium is 

 centrally attached, I have placed with A. incarnata. 



5. Arcyria pomiformis (Leers) Rost. Mon. 27L 1875. 

 Mucor pomiformis Leers, FI. Herborn. 284. 1775. 



Plasmodium white (Lister). Sporangia scattered or gre- 

 garious, stalked, subglobose or ovoid, 0.3 to 0.7 mm. diam., 

 ochraceous yellow; cup plaited at the base, nearly smooth, faintly 

 reticulate or papillose. Stalk slender, buff, 0.2 to 0.4 mm. high, 

 filled with spore-like cells. Capillitium a loose, elastic network 

 of yellowish threads about 3 n diam., marked with transverse 

 bands and spines arranged in an open spiral, nearly smooth else- 

 where. Spores nearly colorless, 6-8 ix diam., marked with a few 

 scattered warts. 



Type locality: Germany. 



Habitat: On dead wood. 



Distribution: Common throughout North America. 



Illustration: Lister, Mycetozoa ed. 3. pi. 176, figs, f, f. 



This species is related to A. cinerea but may be distinguished 

 by the uniformly yellowish color and more open capillitium. 

 Yellow forms are not rare in A. cinerea, but those usually have a 

 very close capillitium, and often a surface net. Var. heterospora 

 G. Lister (Jour. Bot. 71: 221. 1933; N. Y. B. G. no. 8966, type 

 material), from Japan, has not been reported from North America. 



