72 Mycetozoa of North America 



Illustration: Lister, Mycetozoa eel. 3. pi. 56. 



Lister mentions that the inner layer of the convex upper wall 

 has translucent, pale yellow, curved, thickened areas with a 

 vitreous fracture. I have never seen this character in European 

 specimens, and doubt that it is a constant one. The species is 

 distinguished from P. contextum essentially by the spore charac- 

 ters alone. These are somewhat variable in P. contextum, and 

 any one of them may be present, but I have not observed the 

 combination of small, pale, almost smooth spores in any collection 

 from North America or Europe. The specimen personally col- 

 lected in Quebec (N. Y. B. G. no. 4502) has extremely pale and 

 almost smooth spores, but the size is 10-13 n diam. P. contextum 

 is abundant in eastern North America and I have found it fre- 

 quently. It may be that P. conglomeratuni does not occur in 

 North America, or that it is no more than a phase of P. contextum. 

 The specimen in the Herbarium of the New York Botanical Gar- 

 den collected by the Rev. A. B. Langlois at St. Martinville, 

 Louisiana, and distributed by Ellis and Everhart as P. conglo- 

 meratum (Fungi Columbiana no. 1396) is not that species, but 

 typical Physarum hogoriense. 



SZ. Physarum Serpula Morg. Jour. Cin. Soc. Nat. Hist. 19: 29. 

 1896. (N. Y. B. G. No. 11587, authentic material.) 



Plasmodium greenish yellow to yellow (Lister). Sporangia 

 sessile, subglobose, or forming long, straight, flexuose, branched or 

 ring-shaped plasmodiocarps, 0.3 mm. diam., yellow or ochraceous; 

 sporangial wall membranous, with dense, evenly distributed de- 

 posits of \ellow lime-granules. Capillitium of numerous, angular 

 and branching, pale yellow or white lime-knots, connected by 

 short and scanty hyaline threads. Spores purplish brown, spin- 

 ulose, with a paler and smoother area of dehiscence, 10-12 /x diam. 



Type locality: Pennsylvania. 



Habitat: On dead leaves, twigs, and sticks. 



Distribution: Florida, Indiana, *Iowa, Massachusetts, *Ne- 

 braska, New York, North Carolina, Ohio, Ontario, Pennsylvania, 

 Virginia. 



Illustration: Lister, Mycetozoa ed. 3. pi. 57. 



From Bndhamia decipiens, which it often resembles in appear- 

 ance, capillitium and spores, it may be distinguished by the even 

 distribution of the lime in the wall. In B. decipiens this is uneven, 

 making the wall rugulose and veined. The latter is also a stouter 



