CRATERITM.] PHTSARACE.T. 71 



weather the sporangia often lose their colour and become white. 

 Didenna brunnrohtm Phill., from California, Harkness, is allied to this 

 species in the smooth yellow-brown cartilaginous outer sporangium- 

 wall enclosing a densely calcareous inner layer, and in the character of 

 the capillitium. It differs in the sporangia being globose and sessile, 

 in the outer wall being continuous throughout, without a lid of 

 different substance, and in the greater roughness of the spores. It 

 appears to be a single gathering, and if a constant form may constitute 

 a distinct species. 



Hal). On dead leaves, sticks, etc. Lyme Regis, Dorset (L:B.M.45) : 

 Batheaston, Somerset (B. M. 179 to 183) ; Raincliffe Wood, Yorkshire 

 (B. M. 1057) ; France (B. M. 4G9) : Germany (B. M. 473) ; Italy 

 (K. 257) : Sweden (K. 1359); Hungary (K. 1362); Ceylon (B. M. 472); 

 New Zealand (K. 254) ; Pennsylvania (L:B.M.45) ; Iowa (LrB.M.45). 



2. C. concmnum Rex, in Proc. Acad. Nat. Sc. Phil. 1893, 

 p. 370. Plasmodium ? Total height 0*5 to 0*7 mm. Sporangia 

 broadly funnel-shaped or goblet-shaped, stipitate, 0'2 to 0'5 mm. 

 diam., smooth, olive-brown, often paler above, dehiscing by a 

 well- denned convex white lid; sporangium- wall cartilaginous. 

 Stalk brown, O'l to 0'2 mm. long, plicate. Columella none, 

 Capillitium of numerous small angular lime-knots, connected by 

 short and sparingly branched hyaline threads. Spores purplish- 

 brown, minutely warted, 8 to 9 /x diam. 



Plate XXVI., B. a. sporangia, x 20; I. capillitinm an I spores, with 

 fragment of sporangium- wall, x 280; d. spore, x 600 (United States). 



This species is nearly allied to the American form of C. vttlgare, but 

 differs in the smaller size, the brown lime-knots, and the browner 

 spores ; it appears to have been fouud almost exclusively on the burs 

 of chestnut in Fairmount Park, Philadelphia. 



Hab. Philadelphia (L:B3I.46). 



3. C. rubescens Rex, in Proc. Acad. Nat. Sc. Phil. 1893, 

 p. 370. Plasmodium] Sporangium goblet-shaped, stipitate, 

 erect, gregarious, 0'7 to 0'8 mm. high, 0'6 mm. broad, rugose, 

 bright violet, irregularly reticulate with pale violet. Lid 

 convex. Sporangium wall cartilaginous, composed of two or 

 three closely connected layers with deposits of pale violet 

 lime-granules, distributed throughout, but chiefly concentrated 

 in pouch-like cavities of the wall, causing the effect of pale 

 reticulations in the opaque object. Columella represented by a 

 central mass of confluent lime-knots. Stalk cylindrical, 04 mm. 

 high, 0-07 mm. thick, plicate, purple, opaque, arising from a disc- 

 shaped hypothallus. Capillitium of large violet lime-knots, 

 connected by branching pale violet hyaline threads. Spores 

 violet, nearly smooth, 8 to 9 /x diam. Didymium paraguayense 

 Speg., in Anal. Soc. Cient. Argent., xxil, p. 186, No. 320 (1886). 

 Mass., Mon., p. 250. D. guarapiense (errore) Speg., I.e., xxvi., 

 p. 60, No. 154. Physarum pulcherrimum Mass., Mon., p. 293 

 (in part). 



Plate XXVII., A. a, sporangia, x 20 ; b. capillitium and spores, x 280 ; 

 c . spore, x 600 (Paraguay). 



