154 A Monograph of the Myxogastres. 



From 3 4 mm. high; several sporangia fasciculate on a 

 common stem, rarely simple. Closely allied to Arcyria cinerea, 

 differing in the larger size of the sporangia. Sometimes the 

 capillitium and spores are brownish or red. 



(Rostafinski's Synonyms.) 



Stcmonitis digitata, Sz., Amer., f., n. 2350 (1834). 

 Arcyria Leprieurii, Mont, Ann. Sci. Nat., v. iii., p. 141, 

 no. 603 (1855). 



Arcyria Cookei, Mass. (n. sp.). 



Gregarious ; every part Uuish-grey ; sporangia narrowly 

 cylindrical, elongated, wall very thin except the basal portion 

 which persists as a shallow calyculus; stem erect, elongated, 

 very slender, equal, filled with irregular lumps of organic matter ; 

 capillitium dense, becoming protruded elastically during de- 

 hiscence and remaining erect, innermost threads very thin, 

 1'5 2 /x smooth, combined to form a very large-meshed, irregular 

 network, outer threads 4 5 jx thick, densely and uniformly 

 covered with minute warts, forming a small-meshed network; 

 spores globose, smooth, 8 9 /x diameter. 



On wood. Brazil. 



(Type in Herb., Kew.) 



From 3'5 4 mm. high ; stem about equal in length to 

 sporangium. Placed by Dr. Cooke along with Arcyria cinerea, 

 from which it differs in the thin, elongated sporangium, the 

 details of the capillitium, and in the thin long stem being 

 filled with amorphous lumps of organic matter. 



Arcyria dictyonema, Rost. 



Sporangia ovate, stipitate; stems springing in clusters from 

 the substratum, capillitium not very much divided, threads 

 cylindrical, width variable, generally 3'5 p thick, sub-equally 

 covered with an elevated network, the bands of which are spinulose, 

 spines 12 jx high ; spores smooth, 9 10 p diameter. 



