70 THE NORTH AMERICAN SLIME-MOULDS 



peridia in the specimens before us are black or iridescent-black sprin- 

 kled more or less profusely with orange lime granules which sometimes 

 cover all but the base. The stipe, springing from a small hypothallus, 

 is dark red below for about one-fourth its height, then vermillion, 

 above expanding slightly beneath the peridium; the columella scant 

 or none. The capillitium is an elegant delicate net, with numerous 

 small, uniformly regular, calcareous nodes, orange ; by transmitted 

 light, yellow. The spores, brown in mass, are, by transmitted light, 

 pale violet, slightly papillose, 8-10, mostly about 8 /t. The Plasmo- 

 dium is probably yellow. 



This species is no doubt related to P. psittacinum. It is, however, 

 much smaller, has a calcareous stipe, and a much less variegated 

 peridium, and generally a small columella. 



It is also akin to P. globuliferurn and to P. tnurinum, P. petersii 

 Berk. & C. is reported the same thing. 



26. Physarum penetrale Rex. 



Plate XV., Figs. 6, 6 a. 



1891. Physarum penetrale Rex., Proc. Phil. Acad., p. 389. 



1899. Physarum penetrate Rex., Macbr., N. A. S., p. 55 



1911. Physarum penetrale Rex., List., Mycetozoa, 2nd ed., p. 36. 



Sporangia scattered, erect, stipitate, generally ellipsoidal, pyriform, 

 rarely globose ; peridium membranaceous semi-transparent, studded 

 sparsely with rounded, pale yellow or yellow-gray lime-granules, 

 rupturing to the base into two or four segments; stipe variable, 

 slender, subulate, rugulose, flattened laterally toward the base, trans- 

 lucent, dull red or golden red in color; columella four-fifths the 

 height of the sporangium, concolorous with the stipe, acuminate; 

 capillitium dense, persistent, the nodes frequently calcareous, rounded, 

 yellow ; spore-mass brown, spores nearly smooth, brownish, 6-7 fx. 



Readily recognizable by the elongate sporangia and the lengthened 

 columella unique among physarums. The capillitial nodes are at 

 first pale yellow, but tend to whiten on exposure. The spores when 

 highly magnified show delicate spinulescence. 



Maine, New York, Pennsylvania, Ohio, Europe, Java. 



