PHYSAIIUM.J PHYSABACB^. 57 



Berkeley's description of Didymium scrohiculatum that Rostafinski 

 was right in placing it under P. cinereum. There is nothing remaining 

 of the type specimen in Berkeley's Herb. (K. 1518). 



Hob. On dead leaves,., etc. — Lyme Regis, Dorset (L:B.M.32) ; 

 Leytonstone, Essex (L:B.M.32) ; France (Paris Herb.) ; Germany 

 (Strassb. Herb.) ; Natal (K. 2) ; Oeylon (K. 1284) ; Madras (K. 17) ; 

 Pennsylvania (L:B.M.32) ; Iowa (L:B.M.32) ; S. Carolina (B. M. 428, 

 431, 885, 934) ; Cuba (B. M. 429) ; Paraguay (K. 562). 



24. P. bivalve Pers., in TJsteri, Ann. Bet., xv., p. 5 (1795). 

 Plasmodium white, among dead leaves. Sporangia sessile, elon- 

 gated, laterally compressed, sinuous or branched, equal in breadth 

 from the base to the flattened ridge, which at length splits longi- 

 tudinally ; sometimes pulvinate, bursting irregularly ; white, grey, 

 or yellowish ;-sporangium-wall double, the outer layer with copious 

 deposits of lime, smooth or reticulated, the inner wrinkled and 

 colourless, showing as a grey membrane along the line of dehiscence, 

 adhering to the outer layer below. Columella none. Capillitium 

 a network formed of numerous white, often branching lime-knots, 

 varying in shape and size, connected by rather short hyaline 

 threads. Spores violet-brown, spinulose, 8 to 10 ju diam.^.ffie*iCM- 

 Iwria sirvuosa BuU., Champ., p. 94, PI. ccccxlvi., fig. 3 (1791). 

 Angioridiwm sinuosum Grev., Scot. Crypt. Fl., t. 310. Diderma 

 valoatum Fr., Syst. Myc, iii., p. 109. Physarum sinuosum Fr., 

 Syst. Myc, iii., p. 145 ; Rest., Mon., p. 112, lig. 91 ; Cooke, Myx. 

 Brit., p. 14; Mass., Mon., p. 305; Macbride, in Bull. Nat. Hist. 

 Iowa, ii., p. 157. 



Plate XIX., B. — a. sporangium, x 20 ; b. capillitium with fragment of 

 pporangiam-wall and spores, x 280 ; c. spore, x 600 (England). 



Forms without lime occur occasionally in P. bivalve and the allied 

 species. 



Hab. On dead leaves, etc. — Portbury, near Bristol (B. M. 116, 117) ; 

 Leytonstone, Essex (L:B.M.33) ; Luton, Beds. (L:B.M.33); France 

 (K. 28) ; Germany (B. M. 510) ; Finland (B. M. 450) ; Bohemia 

 (B. M. 446) ; Poland (Strassb. Herb.) ; Italy (K. 1345) ; Ceylon 

 (B. M. 451) ; Java (K. 1312) ; Brisbane (B. M. 535) ; Iowa (B. M. 

 811) ; S. Carolina (B. M. 932, 933, 934). 



25. P. Diderma Eost., Mon., p. 110 (1875). Plasmodium white. 

 Sporangia subglobose, 0'6 to 0-8 mm. diam., sessile; or curved and 

 flexuose plasmodiocarps 2 to 6 mm. long, rounded, not compressed, 

 smooth, white or buff; sporangium-wall double, the outer wall 

 densely charged with white lime-granules, free and deciduous 

 above, recurved and persistent below ; inner wall smooth, mem- 

 branous, persistent, of two layers, the outer thin and colourless, 

 combined with the purplish inner layer. Columella none. Capil- 

 litium a network of hyaline threads, with numerous, variously 

 shaped large white lime-knots. Spores dark purplish-brown, 

 spinulose, 10 to 12 /a diam. — Mass., Mon., p. 304 ; List., in Journ. 

 Bot, 1891, p. 260, PI. 309, fig. 2. 



Plate XXII., A. — a. sporangia, x 20 ; b. capillitium with fragment of 

 sporangium and spores, x 280 ; c. spore, x 600 (England). 



