42 BNDOSPOREiE. [pHTSAKUM. 



spores with rather few ovoid brown lime-knots, or a looser net- 

 work of hyahne threads, with numerous elongated irregularly 

 branching lime-knots. Spores pale browmsh-violet, nearly 

 smooth, 8 to 10 /A diam.— i'. Braunianum List, m Journ. Bet. 

 1891, p. 259 (non de Bary). 



- Plate VII., B.— ». sporangia, x 20; T>. plasmodiocarp, x 20; v. capillitium 

 and spores, x 280 ; d. spore, x 600 (United States). 



This species is closely allied to P. globuUferum, from which the 

 stalked form scarcely differs except in the brown colour of the lime 

 in the oapiUitium and sporangium-wall. The specimen from Moffat, 

 described in Journ. Bot., 1891, under the name P. Braunianam de 

 Bary, agrees with de Bary's description of that species in the usually 

 sessile form and brown lime-knots of the capillitium, but as the type 

 consists of only a single gathering by A. Braun near Berlin, and is not 

 represented in the Strassburg or British collections, no proof of identity 

 has been obtained ; the Moffat specimen is therefore placed under 

 P. 7nurinum, the sessile American forms of which it closely resembles. 



Hab. On dead leaves, wood, etc. — Moffat (L:B.M.14) ; Philadelphia ; 

 (L:B.M.14) ; Ohio (L:B.M.14). 



5. P. pulcherrimum Berk. & Rav., in Grev., ii., p. 65 (1873). 

 Total height 1 mm. Sporangia globose, flattened beneath, 

 stipitate, erect or inclined, purple, 0'4 to 0'5 mm. diam., gre- 

 garious. Sporangium-wall membranous, pale purple, with 

 scattered clusters of large purple globular lime granules (1 /a diam.) 

 Stalk purple, subulate, brittle, containing lime. Columella small, 

 convex, or none. Capillitium a close network of delicate purplish 

 threads, broader and more expanded at the axils below ; lime- 

 knots numerous, small, roundish, filled with purple globular lime- 

 granules. Spores pale dull red, almost smooth, 7 to 8 /x diam. 

 — Rost. Mon., p. 106, fig. 84 ; Mass., Mon., p. 293. Physarum 

 atroruhrum Peck, in Rep. New York Mus., xxxi., p. 40 ; Mass., 

 Mon., p. 294. 



Plate VIII., A. — a. sporangia, x 20 ; J. capillitium with fragment of 

 sporangium- wall and spores, x 280 ; c. spore, x 600 (United States). 



P. atroruhrum Peck is the same species (teste Dr. Gr. A. Rex). 



Hah. On dead wood.— Ohio (L:B.M.15) ; Philadelphia (L:B.M.15) ; 

 Iowa (B.M. 1013) ; S. Carolina (B. M. 412, 869). - * 



6. P. citrinum Schumacher, Enum. PI. SadUi., ii., p. 201 (1803). 

 Plasmodium ? Total height 0'8 to 2 mm. Sporangia globose, rugose, 

 stipitate, rarely nearly sessile, erect, yellow to yellowish grey, 

 0-4 to 0-7 mm. diam. ; sporangium-wall membranous with innate 

 clusters of yellow lime granules. Stalk golden yellow, opaque 

 with dense deposits of lime, stout, somewhat furrowed, varying in 

 length, chalky in section, often rising from a vein-like hypo- 

 thallus. Columella short, conical, or obtuse. Capillitium a 

 somewhat close network of hyaUne rigid threads with flat ex- 

 pansions at the axils, persistent after the dispersion of the 

 spores ; lime-knots yellow, numerous, varying in shape and size, 

 usually rounded, seldom developed at the axUs of the branches. 



