44 THE MYXOMYCETES 



y. Golden yellow; capillitium yellow, badhamioid; stipe 



short or lacking 65. P. auriscalpium 



y. Pale yellow or straw colored, rarely gray; dehiscence 



petaloid; stipe slender; nodes small, rounded 66. P. tenerum 



y. Golden yellow; peridium thin; capillitium dense, yellow, 



the nodes few, small and angular 67. P. galbeum 



y. Peridium bright yellow, rough; nodes yellow, dense, con- 

 nected by yellow or hyaline threads 68. P. oblatum 



II. TlLMADOCHE 



o. Plasmodiocarpous, almost aethalioid 69. P. gyrosum 



a. Sporangiate, stalked & 



b. Sporangia compound, gyrose 70. P. polycephalum 



b. Sporangia single c 



c. Spores reticulate; sporangia dull orange to brown 71. P. dictyospermum 



c. Spores not reticulate <* 



d. Gray or white, nodding 72. P. nutans 



d. Yellow, greenish yellow or rusty orange; nodding. ... 73. P. viride 

 d. Iridescent-blue with pale yellow scales; usually erect 



on short stipe 74. P. bethelii 



d. Yellow, orange or iridescent; lenticular, often um- 



bilicate; capillitium rigid, rod-like 75. P. rigidum 



1. Physarum ovisporum G. Lister 



Jour. Bot. 51 :91. 1921. 



Sporangia scattered, sessile, pulvinate or forming straight, curved 

 or irregular plasmodiocarps, 0.5 to 0.8 mm. in diameter, white; spo- 

 rangium wall minutely roughened with deposits of lime granules, often 

 with smoother areas where the lime deposits are scanty; capillitium 

 consisting of numerous white, rounded lime-knots, varying much in 

 size, connected by short hyaline threads; spores rich purple-brown, 

 minutely warted, either globose, 9-11 ju, or oval, 12-13 X 10 fx, often 

 with a pale smooth line of dehiscence. Plasmodium white. 



The above description is based on that of Miss Lister. Specimens 

 from Switzerland, collected and determined by Meylan, have globose 

 spores 9 [x in diameter with no visible area of dehiscence, and closely 

 resemble some forms of P. cinereum, differing only in the longer 

 plasmodiocarps and the somewhat more limy wall. 



England, Switzerland. 



2. Physarum vernum Somm. ex Fries 



Syst. Myc. 3 : 146. 1829. 

 PI. XXI, Fig. 559. 

 1875. Physarum cinereum (Batsch) Pers. ex Rost., Mon. 102, in part. 

 1875. Badhamia verna (Somm.) Rost., Mon. 145, in part. 

 Sporangia sessile, generally plasmodiocarpous, white, nearly smooth, 

 0.5-1 mm. in diameter; peridium firm, usually double, the inner 



