74 THE NORTH AMERICAN SLIME-MOULDS 



1829. Craterium mutabile Fries, Syst. Myc., III., p. 154. 

 1875. Craterium aurenm (Schum.) Rost., Mon., p. 125. 



Sporangia gregarious, globose or obovoid, stipitate, yellow, 

 erect, the peridial wall thin, especially at the summit, where at 

 maturity it breaks up somewhat reticulately, leaving the persist- 

 ent lower portion with an uneven margin above which projects 

 the pale yellow capillitium ; stipe short, orange, or brownish red, 

 arising from a small hypothallus ; capillitium dense, yellow, the 

 nodules not large, irregular, tending to form a pseudo-columella 

 in the centre of the cup ; spores minutely warted, violaceous 

 brown, 8-10 p. 



Fries regards this, which he names C. mutabile, the most dis- 

 tinctly marked species of the genus ; chiefly, as it appears, on 

 account of the bright yellow color. This, however, varies. 

 Some specimens before us are gray, showing only a trace of 

 yellow below. In some European specimens a reddish tinge 

 prevails. The form of the sporangium also varies. In typical 

 specimens, unopened, the shape is almost pyriform ; opened, 

 we have a cylindric, oftenest lemon yellow vase, mounted on a 

 short striate stalk. But again, from the same plasmodium, we 

 may have globose sporangia, opening so as to leave only a 

 shallow, salver-shaped base. In this case the stipe is also 

 longer. The plasmodium is said to be "clear lemon yellow " 

 (Massee). 



There seems little doubt that Schumacher had in mind the 

 present species in his Trichia aurea. Rostafinski shows that 

 Fries's synonym {C. mutabile) is founded on a mistake. The 

 earlier specific name is therefore on Rostafinski's authority 

 adopted. 



Not common. Pennsylvania, New Jersey, North Carolina, 

 Ohio, Iowa. 



2. CRATERIUM MAYDIS Morgan. 



PLATE III., Figs. 6, 6 a. 



1896. Cratcrium maydis Morgan, Jour. Cin. Soc., p. 87. 

 1898. Physarum auriscalpium Cke., Lister, Jour, of Botany, XXXVI., 

 p. 115, (in part). 



