CHONDRIODEBMA.] PHYSAEACB^. 77 



globose, sessile, crowded, 0-5 to 1 mm. diam., seated usually on a 

 strongly developed white hypothallus, smooth or rugose, white ; 

 sporangium-wall of two layers, the outer thick, fragile, composed 

 of globular lime-granules 1 to 2 /x. diam., often crumbling away 

 from the membranous, more persistent inner layer, sometimes 

 inseparable. Columella convex or hemispherical, white or pale 

 flesh-coloured. Oapillitium of slender, flexuose, purplish threads, 

 branching at an acute angle and somewhat anastomosing. Spores 

 violet-brown, spinulose, 8 to 11 /x diam. — Cooke, Myx. Brit., 

 p. 38. BidymivMi spwmarioides Fr., Symb. Gast., p. 20 (1818) ; 

 Mass., Mon., p. 232. Physarum stromatev/m Link, Handb., iii., 

 p. 409 (1833). Ghondrioderma stromatevmi Rost., Mon., App., 

 p. 18. Ghondrioderma virgineum Mass., Mon., p. 207. 



Plate XXIX., B. — a. sporangia, x 20 ; J. capilHtium, with fragment of 

 sporangium-wall and spores, x 280 ; o. spore, x 600 (England). 



The type specimen of 0. mrginewm Mass. (K. 560) is a frequent 

 form of G. spwmarioides without hypothallus ; the oapillitium in some 

 sporangia is normal and without expansions. The type specimen of 

 C. stromateum Rost. in the Strassb. Herb, is from Lochem (leg. Spree, 

 Rab. Fung. Eur., 432) ; a part of this gathering is in the British 

 Museum (B. M. 515) ; it does not appear to present any character by 

 which it can be separated from C. spumarioides. 



Hah. On dead leaves,etc. Common. — Lyme Regis,Dorset (L :B.M.52) ; 

 France (K. 37) ; Germany (B. M. 515) ; New York (B. M. 886) ; 



Mass., U.S.A. (L:B.M.52). 



2. C. subdictyospermum Rost., Mon., App., p. 16 (1876). 

 Plasmodium ? Sporangia subglobose, sessile, crowded, 0-3 to 

 0'5 mm. diam., snow-white, seated on a well-developed white 

 hypothallus ; sporangium-wall thick, fragile, composed of an 

 outer crust of globular lime-granules 2 /x diam., with a delicate, 

 membranotis, inseparable inner layer. Columella hemispherical 

 or subglobose, white. Oapillitium of somewhat rigid, violet-brown, 

 sparingly branched threads. Spores violet-brown, reticulated 

 with raised ridges or with broken bands, forming a margin about 

 2 fA, broad; 10 to 12 /a diam. — Didyrmum dealhatwm Berk. & 

 Curt., in Herb. GJumdrioderma dealhata Mass., Mon., p. 207. 



Plate XXX., B. — d. sporangia, x 20 ; e. oapillitium and spores, x 280 ; 

 /. spore, X 600 (Venezuela, Rostafinski's type) ; g. spore, x 600 (Cape). 



This species appears to be allied to C. spumarioides, difEering 

 essentially in the spores. It is represented by two gatherings. One 

 is from Venezuela, named Didymium dealbatum Berk. & Curt. 

 (B. M. 570 ; K. 1522) ; this is the type given by Rostafinski (Mon., 

 App., p. 16), and accurately described as having spores provided with 

 protuberances either irregularly disposed or combined into an incomplete 

 net. The other gathering is in the Kew collection (K. 466), named 

 Didymium physa/roides, Cape 198 ; in this specimen the spores are more 

 perfectly reticulated, and, except in colour, resemj)le those of Trichia 

 favoginea Pers. ; the oapillitium is also more flexuose. 



3ab. On moss.— Cape (K. 466) ; Venezuela (B. M. 570). 



