34 THE MYXOMYCETES 



dense at the center, radiant at the periphery where it meets the spo- 

 rangial wall, white; spores violaceous black, minutely warted, 12-14 /x. 

 Plasmodium cream to pale yellow. 



This is a beautiful species, easily known by its discoidal or almost 

 annulate sporangia mounted upon short, dark stipes. The stipe 

 in western collections is sometimes very short, but generally suffices to 

 raise the sporangium, a little at least, above the substratum. Sessile 

 and plasmodiocarpous forms do occur with the typical stipitate phase, 

 but may be regarded here as elsewhere as indicative of incomplete 

 development. Miss Lister regards this as a variety of B. affinis, to 

 which species it undoubtedly is related. But its larger size, somewhat 

 smaller spores and slight but apparently constant differences in perid- 

 ium and capillitium seem to justify its retention as a distinct species. 



Pennsylvania, Ohio, Iowa, Nebraska, South Dakota, Colorado, 

 Antigua; Malay Peninsula, Manchuria, Japan. 



13. Badhamia macrocarpa (Ces.) Rost. 



Mon. 143. 1875. 

 PI. II, Figs. 31, 32. 



1855. Physarum macrocarpon Cesati, Flora 38 : 271. 



Sporangia scattered, closely aggregate or crowded, globose or sub- 

 globose, 0.5-1.0 mm. in diameter, sessile or with a pale yellowish or 

 brownish furrowed or submembranaceous stalk; peridium rugulose, 

 white above, below yellowish or brownish; capillitium not abundant, 

 thoroughly calcareous, the nodes broad, conspicuous, the connecting 

 tubules rigid; columella none; hypothallus scant or none; spore-mass 

 black, spores non-adherent, by transmitted light dark violet-brown, 

 finely but densely and somewhat irregularly spinulose all over, spher- 

 ical, 11-14 /d. 



Externally closely resembling B. panicea, but easily distinguished by 

 the larger, more spinulose spores. European authors describe both 

 sessile and stipitate forms. American specimens generally are sessile 

 and for the most part closely crowded, almost heaped. Professor 

 Bethel has reported this in winter everywhere on fallen rotting stems 

 of Opuntia and on the bases of dead Yucca leaves, still attached. 

 Occasionally associated with the typical phase and often occurring 

 alone was a discoidal form which when first seen (in 1908) was called 

 var. gracilis, under which name Miss Lister distinguishes it. Further 

 study suggests that the latter is best regarded as a distinct species, as 

 it differs not only in its external characters but in its spores, which in 

 gracilis are not only warted, but possess a coarse reticulation in addi- 



