THE JOURNAL OF BOTANY 



again in December, 1S94, in fir plantations at Leigbton Buzzard, 

 Bedfordshire, where fchey appeared on pine bark and dead leaves. 

 The gatherings were small, and my father and I thought they 

 might be considered an irregular sessile form of Lamproderma 



imbinum (see Brit. Mus. Cat. ed. 1, p. 126, and ed. 2, fig. 131 h). 

 In November, 11*11, Miss Katherine Higgins found abundant 



rangia on leaves' and twigs amongst the lower parts of whortle- 

 berry bushes at Woburn Sands, Beds; they were both in mature 



lit ion, and arising from dirty-looking drab plasmodium. Last 



bomber, Miss Hibbert- Ware and I obtained the same form in 

 moist spruce woods near Miirren, Switzerland, and also in the 

 ancient pine forest of Rothiemurchas, in the north of Scotland. 

 1 have since received it from M. Oh. Meylan, who gathered it in 

 woods near La Vaux, in the Jura Mountains, about 4000 ft. alt., 

 not far from Neuchatel, in October last. All the specimens show 

 the same features, except that the minute crystalline scales of 

 lime are present in the walls of some sporangia and absent from 

 others. 



Diderma arboreum G. Lister & Petch, sp. n. Plasmodium? 

 Sporangia scattered, discoid or saucer-shaped, 0'5 mm. diam., 



rile or shortly stalked, or forming irregularly expanded flattened 

 plasiuodiocarps 1 to 3 mm. diam., white, or purplish-grey when 

 lime-deposits are scanty, smooth or wrinkled; sporangium-wall 

 fragile, colourless, pale purplish or brownish, usually invested with 

 an outer crust of minute round lime granules ; these, however, 

 may be absent, or represented by scattered irregular fragments of 

 lime. Stalk pale reddish-brown or nearly black, rugose, stout or 

 Blender, 0-1 mm. high. Columella convex and flesh-coloured, or 



ent. Capillitium consisting of simple or branched, colour- 

 less or purplish threads, 1-5 to 3 /j. diam., often anastomosing 

 and showing irregular expansions near the extremities. Spores 

 10 to 15 \>. diam., pale purplish or purplish-brown, minutely 

 Bpinulose. 



Habitat. On moss, lichens, and bark, on the trunks of living 



This species is allied to D. effnsum Morgan, from which it 

 differs In the stouter capillitium, the larger spores, and in the 

 sporangia being sometimes stalked. It has been obtained from 

 three widely separated regions— Ceylon, Japan, and Scotland. It 

 was first found in May, 11)06, by Mr. T. Petch in Ceylon, at Pera- 

 deniya, 1600 ft. alt., and at Talawakelle, 4000 ft. alt. ; and again 



I 'eradeniya in August, 190G. On first sending a specimen to my 

 father, Mr. Petch suggested that the specific name "arboreum" 

 might be appropriate, from the arboreal habit of the sporangia ; 

 however, were then inclined to regard it as a sessile form of 

 Diderma rugosum, under which name Mr. Petch refers to it in the 

 Annals of the Royal Botanic Gardens, Peradeniya, iv. 345 (1910). 



In Japan, Mr. Kumagusu Minakata obtained similar sporangia 

 in the summers of 1906, 1907, and 1909, in the province of Kii, 

 on the living trunks of Primus Mume Sieb. & Zucc, P. persica 

 Sieb. & Zucc, and Celtis sinensis Pers. These Japanese gather- 



