254 THE NORTH AMERICAN SLIME-MOULDS 



form around the thread a lengthened spiral ; spore-mass red or reddish 

 brown, spores by transmitted light colorless, nearly smooth, 6—8 /x. 



This species is easily distinguished from all other of similar tints 

 by the attachment of the capillitium. In this respect it corresponds 

 with the following species. In the adornment of the threads it is 

 like A. incarnata. It is by far the commonest species of the genus, 

 and probably enjoys a world-wide distribution. To be found at 

 all seasons on the lower side of fallen sticks, Populus, Tilia, etc. 



Micheli, PI. XCIV., shows that he had the present species. The 

 description given by Linne is worthless, but helped out by Micheli, and 

 several other authors of the eighteenth century, who take the trouble 

 to describe the species, but still give the Linnean binomial as a syn- 

 onym ; we may give Linne here the credit. As a matter of fact, 

 Batsch under Embolus crocatus first presents an unmistakable de- 

 scription and figure. 



Maine to the Black Hills and Colorado, and north and west; 

 Alaska to Nicaragua. 



9. Arcyria cinerea {Bull. ) Pers. 



Plate II., Figs. 3, 3 a. 



1791. Trichia cinerea Bull., Champ, de France, p. 120, Tab. 477, Fig. iii 

 1801. Arcyria cinerea (Bull.) Pers., Syn. Fung., p. 184. 



Sporangia scattered or gregarious, ovoid or cylindrical, generally 

 tapering upward, about 2-3 mm. high, ashen gray, sometimes with 

 a yellowish tinge, stipitate; calyculus very small, thin; stipe about 

 half the total height, rising from a small hypothallus, thin, gray 

 or blackish, densely crowded with spore-like cells; capillitium dense, 

 freely branching, ashen, or yellowish, little wider below, minutely 

 spinulose; spore-mass concolorous, spores by transmitted light color- 

 less, smooth, 6-7 jx. 



A very common little species, easily recognized by its color and 

 habit. The capillitium is more dense than in any other species and 

 expands less. The stipe is about equal to the expanded capillitium, 

 unusually long. The Plasmodium occurs in rotten wood, especially 

 species of Tilia, is gray and, judging from the number of sporangia 

 found in one place, scanty. 



