PHYSARUM 29 



Sporangia distinct or plasmodiocarpous, the plasmodiocarp 

 creeping in long vein-like reticulations or curves, laterally 

 compressed ; sometimes distinct and crowded, always sessile. 

 Peridium double ; the outer thick, calcareous, fragile, snow- 

 white ; the inner delicate, the dehiscence by longitudinal fissure. 

 Capillitium strongly developed with abundant white, calcareous 

 granules. Spores smooth, dull violet, 8-9 /a. 



Easily recognized at sight by its peculiar form, bilabiate and 

 sinuous. Apart from microscopic structure perfectly described 

 by Fries, Syst. Myc., p. 145. Bulliard called it Reticularia 

 simiosa. Habitat various, but not infrequently the upper sur- 

 face of the leaves of living plants, a few inches from the ground. 

 The two sorts of fructification often occur side by side, or merge 

 into one another from the same pla^modium. Where the sub- 

 stratum affords room the plasmodiocarpous style prevails ; in 

 narrower limits the sporangia stand singly. The calcareous de- 

 posit on the outer peridium is very rich and under a lens appears 

 made up of countless snowy or creamy flakes. N.A.F., 1394. 



Widely distributed. New England to the Carolinas, and 

 Louisiana, west to South Dakota and Nebraska. 



3. PHYSARUM SERPULA Morg. 



PLATE IX., Figs. 6, 6 a, and 6 b. 



1831. Physarum reticidatiim Alb. and Schw., Schweinitz, N. A. F., 

 No. 2295. 



1885. Physarum gyrosum (Rost.) Wingate, Ellis, N. A. F., No. 1396. 



1892. Pliysaritm gyrosum Rost., Massee, Mon., p. 307. 



1892. Cienkowskia reticulata Rost., Macbride, Bull. Nat. Hist. Iowa, 

 II. 2, p. 150. 



1894. Badhamia decipiens Berk., Lister, Mycetozoa, p. 33 (in part). 



1896. Physarum serpula Morgan, Cin. Soc. Nat. Hist., p. 101. 



Plasmodiocarp repent, reticulate, forming anon lines, circles, 

 dots, etc., venulose, pale yellow, ochraceous, at length whitish ; 

 the peridium thin, membranaceous, simple, fragile, but withal 

 persistent, below united with a hypothallus which is more or 

 less widely produced ; capillitium rather scant, but abundantly 



