82 ENDOSPOREAE [PHYSARUM 



This species was first discovered by tin- Rev. W. Cran in the 

 island of Dominica in 1897 ; in July, L902, it was collected in Bolivia 

 by Dr R. E. Fries, who established its right to specific rank ; since then 

 large gatherings have been made in the island of Santa Cruz, West 

 I in lies, by Prof. C. Raunkiaer. In the Dominicia specimen the lime- 

 knots are more angular than in those from Bolivia and Santa Cruz, 

 but in other respects the gatherings are very similar. 



Hab. On dead palm leaves, twigs, etc. — Dominica (B.M. 1643); 

 Santa Cruz, West Indies (B.M. 2316) ; near Tarija, Bolivia (B.M. 2313). 



54. P. rubiginosum Fries Symb. Gast., 21 (1817). Plasmo- 

 dium orange-red {fide Schroeter). Sporangia subglobose, 

 0*5 to 1 mm. diam., sessile, gregarious or crowded, smooth 

 or rugulose, scarlet, reddish- or olive-brown ; sporangium- 

 wall membranous, with dense included clusters of orange 

 lime-granules. Columella none. Capillitium an abundant 

 network of hyaline threads with frequent triangular 

 membranous expansions at the axils of the branches ; lime- 

 knots large, angular, branching, orange-red or red-brown. 

 Spores pale violet-brown, spinulose, 8 to 11/x diam. — Rost. 

 Mon., p. 104 ; Blytt in Bidr. Norg., Sop., iii. 4 ; Schroeter 

 in Cohn Krypt. FL Schles., hi., pt. 1, 129 ; Mass. Mon., 302. 

 P. fulvum Fr. Syst. Myc, iii. 143 (1829). 



Pi. 59. — a. sporangia (Brandenburg) ; b. sporangia (New York) ; c. capillitium and 

 spores, with fragment of sporangium-wall ; d. spore. 



Closely allied to P. auriscalpium from which it differs in the redder 

 colour and sessile habit of the sporangia and in the more abundant 

 hyaline network of the capillitium. A gathering from Philadelphia 

 sent by Mr. Wingate to Mr. Massee under the name of Leocarpus 

 squamulosus has glossy red-brown sporangia and dark red-brown 

 capillitium ; another from Gaddonfield, New York, collected by Dr. 

 Sturgis, has similar capillitium and orange-red sporangia fading where 

 exposed to strong light to a dull ochraceous colour ; in all other respects 

 these gatherings agree with the typical form of P. rubiginosum. 



Hab. On dead wood and moss.— Brandenburg (B.M. 2317) ; 

 Norway (B.M. 2318) ; Philadelphia (B.M. 2319). 



55. P. lateritium Morgan Myx. Miami Valley, 95 

 (1896). Plasmodium ? Sporangia subglobose, 0-3 to 

 0-7 mm. diam., sessile, or forming simple branched 

 or net-like plasmodiocarps, terete or laterally compressed, 

 gregarious, more rarely clustered, orange, brick-red, rosy- 

 red, or red-brown, somewhat rugose, rupturing irregularly ; 

 sporangium-wall membranous, colourless above, yellow at the 

 base, with included clusters of red or orange lime-granules. 

 Columella none. Capillitium a network of slender colour- 

 less or pale yellow threads, with rounded lime-knots varying 

 in shape and size, the knots orange, or showing red centres 

 surrounded by yellowish round lime-granules. Spores pale 

 brownish- violet, almost smooth, 6 to 9 ^ diam. — Macbride 

 N. Am. Slime Moulds, 33 (1899). Didymium lateritium 



