578 Seaver: North Dakota slime- moulds 



plants and often some distance above ground, an adaptation for 

 spore distribution. 



losum (Albert. & Schwein.) Fries. 

 On leaves and decaying materials of various kinds. A com- 

 mon species. 



Fuligo ovata (Schaeff.) Macbr. 



This is a common species and one which often attains consid- 

 erable size. One specimen collected on a rotten log in North 

 Dakota was from six to eight inches in diameter and smaller speci- 

 mens were found to be very common. 



Physarum contextum Pers. 



Several collections were made on decaying materials of van- 



ous kinds in woods near Fargo. 



Tilmadoche viridis (Bull.) Sacc. 



Plants collected on rotten wood. The species is not uncom- 

 mon and has a wide distribution. 



STEMONITACEAE 



Stemonitis maxima Schwein. 



Numerous specimens were collected on bark and wood o 

 Tilia americana, for which substratum it shows a decided prefer- 

 ence. Widely distributed. 



Stemonitis Smith ii Macbr. 



The specimens, collected in similar localities to the preceding, 

 were mostly larger and easily distinguished from that species y 

 the color of the spore mass, which is ferruginous instead of pur- 

 plish black. Rather common. 



CRIBRARIACEAE 



Dictydiaethalium plumbeum (Schum.) Rost. 



Several collections on decaying wood. The plants a 

 pressed and spread out, becoming 1-2 cm. in diameter an re b 

 nized by these characters and the ochraceous color, 

 species known to North America has a wide distribution. 



Dictydium cancellatum (Batsch) Macbr. . 



One of the most variable species of the group, the plants 

 either long- or short-stemmed and very variable in color. 



