74 THE NORTH AMERICAN SLIME-MOULDS 



delicate, with more or less well-developed nodules, which are also 

 concolorous; spores by transmitted light, dark brown, thick-walled, 

 rough, nucleated, about 10 fi. 



A very handsome little species collected by Professor G. W. New- 

 ton in Colorado, at an altitude of several thousand feet. Easily 

 recognized by its almost sessile, rose purple, generally umbilicate 

 sporangium. 



31. Physarum psittacinum Ditm. 



1817. Physarum psittacinum Ditm., Sturm, Deutsch. Fl. Pilze, p. 125. 



1829. Physarum psittacinum Ditm., Fries, Syst. Myc, III., p. 134. 



1873. Physarum psittacinum Ditm., Rost, Mon., p. 104. 



1911. Physarum psittacinum Ditm., Lister, Mycetozoa, 2nd ed., p. 55. 



Sporangia scattered or gregarious, globose or depressed-globose, 

 or reniform, iridescent-blue, mottled with various tints, red, orange, 

 yellow, white, stipitate; stipe equal, or tapering slightly upward, 

 rugose, orange or orange red, without lime, rising from a small con- 

 colorous hypothallus ; columella none ; capillitium dense, crowded 

 with calcareous, brilliant orange nodules which are angular in outline 

 and tend to aggregate at the centre of the sporangium; spore-mass 

 brown ; spores by transmitted light, pale brown, slightly but plainly 

 warted, about 10 /a. N. A. F., 2492. 



Differs from P. pulcherripes Pk. in external coloration, the perid- 

 ium a rich blue, mottled but not with lime ; in the capillitium, dense, 

 calcareous, with large angular or branching nodes; in the stipe with- 

 out lime; in the spores, a little larger than in P. pulcherripes, and 

 by transmitted light much more distinctly brown in color. The 

 sporangia are also broader in the present species, reaching 1 mm. 



Rare. Maine, New York, Massachusetts, Pennsylvania. Re- 

 ported common in Europe, Ceylon, Japan, etc. 



32. Physarum discoidale Macbr. n. s. 



Plate XX., Figs. 3 and 3 a. 



Sporangia gregarious, scattered, discoidal, depressed or umbilicate 

 above, sometimes almost annulate, snow-white, small, .5-.7 mm., 

 stipitate; stipe about twice the sporangium, pale yellow, strand-like. 



