ARCYRIA 189 



white ; as it approaches maturity a rosy metallic tinge supervenes, 

 quickly changing to dull yellow or alutaceous. The graphic 

 description given by Fries of PericJicena incarnata, Syst. Myc. t 

 III., p. 193, presents scarcely a character attributable to the form 

 before us. L. congesta Berk, and Br., evidently the form figured 

 and described by Lister, Mycetozoa, p. 194, PL Ixx., B., resembles 

 our species in color and capillitium, but is entirely different in 

 habit. 



Not common. Maine, Iowa, Missouri, Nebraska. 



2. Arcyria (Hill} Pers. 



1751. Arcyria Sir John Hill, Gen. Nat. Hist., II., p. 47. 

 1801. Arcyria Persoon, Syn. Fung., p. 182. 



Sporangia ovoid or cylindric or even globose, stipitate; the 

 peridium thin, evanescent to near the base, the lower part per- 

 sisting as a calyculus ; the stipe variable, but packed with free 

 cell-like vesicles, resembling spores, but larger; capillitium 

 attached below, to the interior of the stipe or to the calyculus, 

 in form an elastic network, the tubules adorned with warts, 

 spinules, half-rings, etc., but without spiral bands or free 

 extremities. 



Micheli, of course, discovered the Arcyrias, put them in two 

 genera and several species, which we may only dimly recog- 

 nize. Persoon first saw distinctly the outlines of the genus as 

 now understood and adopted the name given by Hill in his 

 curiously prolix description of certain species, probably partly 

 of the genus Arcyria, partly Stemonitis. 



Key to the Species of Arcyria. 



A. Mature capillitium loosely adhering to the calyculus. 



a. Mature capillitium far-expanded, drooping. 



i. Dusky. 



* Long, 12 mm. or more . . . I. A. inagna 



** Shorter, about 6 mm. . . . 2. A. ozrstedtii 



ii. Yellow 3. A. nutans 



b. Mature capillitium short, not drooping, though sometimes pro- 



cumbent. 



