64 ENDOSPOREAE [PHYSARUM 



subulate or nearly cylindrical, 0-7 to To mm. long, longitudin- 

 ally rugose, pale buff or yellow, translucent above, without 

 deposits of lime, enclosing refuse matter at the base. Columella 

 none. Capillitium a close persistent network of very slender 

 colourless threads with scattered minute rounded white lime- 

 knots ; in the centre of the capillitium is usually suspended 

 a shining white calcareous ball, 0-1 to 0-15 mm. diam., some- 

 times replaced by a cluster of irregular lime-knots ; lime- 

 granules, 1 to 2 jx, diam. Spores pale violet-brown, minutely 

 spinulose. 6 to 7 n diam. — Macbride N. Am. Slime-Moulds, 54 ; 

 P. simile Rost. Mon., App. p. 6 (1876) ?; Mass. Mon., 286? 



PI. 35. — a. sporangia (Philadelphia) ; b. capillitium showing the central calcareous 

 ball surrounded by small lime-knots ; c. spore. 



The type specimen of P. simile Rost., from Curtis, South Carolina 

 (K. 1255), has buff stalks without lime deposits, and delicate persistent 

 capillitium with a central mass of lime ; it is a poor development and 

 in imperfect preservation ; perhaps it should be referred to the present 

 species, although Rostafmski's description of P. simile with the stalk 

 continued into the sporangium as a cylindrical columella would apply 

 better to P. globuliferum (see Rost. Mon., App. p. 6). 



Hob. On dead wood.— Philadelphia (B.M. 2155) ; Iowa (B.M. 1019) ; 

 Antigua (B.M. slide) ; Java (B.M. 2156) ; Borneo (B.M. 2157) ; Japan 

 (B.M. 1991). 



31. P. straminipes Lister in Journ. Bot., xxxvi. 163, 

 t. 386, fig. 2 (1898). Plasmodium milk-white. Sporangia greyish- 

 white, obovoid or wedge-shaped, 0*7 mm. diam., clustered or 

 scattered, on long or short stalks, two or more often borne on 

 a single stalk, or sessile and subglobose or irregularly ellipsoid ; 

 sporangium-wall colourless or pale purple, membranous, 

 rather firm, with dense included clusters of lime-granules. 

 Stalks straw-coloured, translucent, often 2mm. long, membran- 

 ous or cartilaginous, flattened or filiform, free from refuse 

 matter, often continued below into a strand-like hypothallus. 

 Capillitium a persistent network of stout rigid hyaline threads 

 with expansions at the axils, and numerous rounded white 

 lime-knots, some of which often unite to form a pseudo- 

 columella. Spores 10 to 11 /x diam., purple-brown, marked 

 with broad patches of warts separated by smoother tracts. 

 — Torrend Fl. Myx., 197. 



PI. 42. — a. sporangia (Lyme Regis) ; b. capillitium and spores ; c. spore. 



Allied to P. compressum, but distinguished by the long slender 

 translucent stalks, the rigid capillitium, and the peculiar distribution of 

 warts on the spores. 



Hab. On dead leaves, straw, etc. — Beds (B.M. 1709) ; Lyme Regis 

 (B.M. 1700) ; Norfolk (B.M. 2163) ; Somerset (B.M. 2164) ; Aberdeen 

 (B.M. 2165) ; Berlin (B.M. 2166). 



32. P. pusillum Lister. Plasmodium watery-white. 

 Total height 1 to 2 mm. Sporangia subglobose, rarely obovoid 



