THE 



JOURNAL OF BOTANY 



BKITISH 4ND FOREIGN. 



• UB*A*T 



NEW MYCETOZOA. BOTANICAL 

 By G. Lister, F.L.S. *»** wBI 



(Plates 524, 525.) 



Leptoderma, gen. n. 



Sporangia sessile or shortly stalked; sporangium-wall mem- 

 branous, hyaline in the upper part, in the lower part thickened 

 with granular deposits, and sometimes including minute crystalline 

 scales of carbonate of lime. Stalk black, enclosing refuse matter. 

 Capillitium consisting of rigid, branched, and anastomosing black 

 threads. Spores purplish-grey. 



L. iridescens, sp. unica. Plasmodium drab-coloured. Spor- 

 angia scattered or in small clusters, globose or hemispherical, 

 0*5 to 0-8 mm. diam., sessile, rarely shortly stalked, greyish- 

 purple or purplish-brown, glossy, iridescent, dehiscing irregularly ; 

 sporangium-wall nearly colourless in the upper part, thickened 

 and veined below with embedded deposits of brown granules, 

 sometimes including also scattered crystalline scales of lime from 

 2 to 15 /x diam. Stalk very short, stout, appearing nearly black 

 from the dark refuse matter enclosed by its pale walls, spreading 

 below into a membranous hypothallus which is also charged with 

 refuse matter. Columella none. Capillitium consisting of a 

 persistent network of slender black threads, colourless at the 

 extremities, radiating from the floor of the sporangium ; the pale 

 bases of the threads are often tubular and expanded, enclos- 

 ing granular matter. Spores purplish-grey, spinulose, 10 to 

 11 [x diam. 



Habitat. On pine-bark, twigs, leaves, &c. 



This genus appears to be allied to Lamprodcrma, from which 

 it differs in the thickened sporangium-wall, and the occasional 

 presence there of deposits of carbonate of lime; also in the stalk 

 enclosing refuse matter. It is more nearly allied to Lcpidoderma, 

 from which it is distinguished by the sporangium-wall being 

 membranous, not cartilaginous, and from the deposits of lime 

 being very scanty or absent. 



I first found the dusky little sporangia in March, 1892, and 

 Journal of Botany.— Vol. 51. [January, 1913.] b 



