physakum] physaraceae 47 



larger and darker spores. The graphic description of P. flavum Fr., 

 with its rugose but glossy (glaberrima) yellow sporangia and short 

 yellowish- white furrowed stalks, applies well to the present species. 

 In Sy sterna Mycologium, p. 135, Fries places P. flavum next after P. 

 sulphureum ; the distinctions he makes between the two species are 

 the bright yellow rather than sulphur-coloured sporangia and yellow not 

 white stalks of P. flavum ; sporangia showing varying shades of bright- 

 ness, with white or yellowish stalks, may however occur in a single 

 group of P. sulphureum. The type of P. lepidodermoides BlyttfromRollag, 

 Telemarken, on moss (B. M. slide), has subglobose stalked sporangia, 

 - 7 to 0'8 mm. diam. ; the sporangium-wall breaks up into shining 

 convex pale brown scales, densely charged with deposits of lime ; there 

 is no columella ; the stalks are 0'5 mm. high, stout, furrowed, broader 

 at the base, cream-white, without lime-deposits ; the capillitium con- 

 sists of large irregular shrunken whitish lime-knots connected by 

 branching hyaline threads ; the s23ores are purple-brown, spinulose, 

 9 to 11 /JL diam. ; the scales of the sporangium-wall and the shrunken 

 lime-knots suggest that this is not a perfect development ; probably 

 it is a form of P. sulphureum, in which we have met with some sporangia 

 having almost no lime in the stalk associated with others whose stalks 

 are rich in lime. P. lepidodermoides bears some resemblance to P. 

 citrinellum Peck, but the stalks are cream-white, not orange-red as in the 

 latter species. 



Hob. On dead leaves. — Upsala (B.M. 2095) ; Brandenburg (B.M. 

 2096). 



4. P. variabile Rex in Proc. Acad. Nat. Sci. Phil., 1893, 371. 

 Plasmodium ? Total height about 1 mm. Sporangia gregarious, 

 piriform, ovoid, or subglobose, 0*4 to 0-5 mm. broad, stalked 

 or sessile, rugose, often somewhat glossy, yellowish-olive ; 

 sporangium- wall membranous, with dense innate deposits of 

 yellowish lime-granules. Stalk stout, conical, furrowed, 

 0-4 mm. high or less, yellowish-brown, densely charged with 

 white lime-granules. Columella none. Capillitium a close 

 network of slender hyaline threads with membranous 

 expansions at the axils of the branches ; lime-knots numerous, 

 irregularly branching, many large and confluent, white or 

 pale yellow. Spores brownish- violet, spinulose, 9 to 10 ^ 

 diam. — Macbr. N. Am. Slime-Moulds, 39. 



Var. sessile Lister in Journ. Bot., xxxvi. 114 (1898) : 

 sporangia sessile, forming curved branching plasmodiocarps, 

 yellow or bright orange, occasionally almost white. — Petch 

 in Ann. Perad., iv. 329. 



PI. 21. — a. sporangia ; b. capillitium and spores ; c. spore ; (New York). 



PI. 22. — var. gessile : a. sporangia (Philadelphia) ; b. sporangia (Antigua) ; c. capilli- 

 tium and spores ; d. spore. 



Hob. On dead leaves.— Banff, Canada (B.M. 3189) ; Iowa (B.M. 

 812); New York (B.M. slide) ; Venezuela (B.M. slide): var. sessile — 

 Antigua (B.M. 1644) ; Philadelphia (B.M. 2097) ; South Carolina 

 (B.M. 991); Ceylon (B.M. 2098). 



