ARCYRIA 247 



scriptions of European forms and comparison of many specimens leads 

 us to believe that we have here to do with a type presenting constant 

 peculiarities. We have in America nothing to correspond with the 

 figures of Schweinitz, Berkeley, or Lister. In the American gather- 

 ings the sporangia are uniformly regular, globose, very generally 

 short-stipitate, more or less closely gregarious, never superimposed, 

 or heaped as shown in Berkeley's figure, for instance, Ann. and Mag. 

 Nat. Hist., IV., xvii., PI. ix.. Fig. 2. The Plasmodium of our species 

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

 quickly changing to dull yellow or alutaceous. The graphic descrip- 

 tion given by Fries of Perichaena incamata, Syst. Myc, III., p. 193, 

 presents scarcely a character attributable to the form before us. L. 

 congesta Berk. & Br., evidently the form figured and described by 

 Lister, Mycetozoa, p. 194, PI. Ixx., B., resembles our species in color 

 and capillitium, but is entirely different in habit. 



Not uncommon. Maine, Iowa, Missouri, Nebraska. 



2. Arcyria {Hill) Pers. 



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

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



Sporangia ovoid or cylindric or even globose, stipitate; the peridium 

 thin, evanescent to near the base, the lower part persisting as a calyc- 

 ulus ; the stipe variable, packed with free cell-like vesicles, resem- 

 bling 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 recognize. 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 Ste- 

 monitis. 



Key to the Species of Arcyria 



A. Mature capillitium loosely adhering to the calyculus. 

 a. Mature capillitium far-expanded, drooping. 



