lamproderma] stemonitaceae 167 



Var. 1. Sauteri Lister: sporangia globose, or ovoid-globose ; 

 capillitium brown; spores purple-brown, 11 to 15 /x diam., 

 nearly smooth or spinose. — L. Sauteri Rost. Mon., p. 205 ; 

 Mass. Mon., 100 ; Macbr. N. Am. Slime-Moulds, 140. L. 

 robustum Ellis & Everli. in Mass. I.e., 99. L. arcyrioides 

 Morg. Myx. Miami Valley, 47 (1894). 



Var. 2. Carestiae Lister : sporangia globose or ovoid, nearly 

 black, shortly stalked or quite sessile ; capillitium dark 

 purple-brown, forming either a dense network or consisting of 

 almost straight threads ; spores purple-brown, closely spinulose 

 or spinose, 9 to 16 /x diam. — Stemonitis Carestiae Ces. & de 

 Not. Erb. Crit. Ital., no. 888. 



Var. 3. dictyosporum Lister : resembling var. Carestiae, but 

 with purplish-grey spores 10 to 14 /x, marked with spinules 

 and short ridges more or less united to form an irregular 

 reticulation. — Lister in Journ. Bot., xlvi. 218 (1908). 



PI. 132. — a. b. sporangia (England) ; c. capillitium and columella ; d. e. spores 

 /. sporangium of var. Sauteri (Salzburg) ; g. m. spores of same ; h. sporangia of var 

 Carestiae (North Italy) ; i. capillitium and columella of same ; /.•. I. spores of same. 



PI. 133. — /. sporangia of var. dictyosporum (Switzerland) ; g. sporangia of same 

 after dispersion of spores ; h. i. spores. 



This species is abundant in the British Isles, in Europe and in North 



America. The varieties given above are well-marked centres, round 



which intermediate forms group themselves, but neither the size of the 



spores, the colour of the capillitium, nor the shape of the sporangia 



can be taken as giving constant specific characters. The typical 



form appears to be usually found in the lowlands ; the three varieties 



are essentially alpine forms. Gatherings made near Lyme Regis show 



great variety of capillitium ; even in a single development it 



may be either nearly colourless and flaccid, or brown and rigid, the 



associated spores being pale violet-grey, closely and minutely spinulose, 



8 to 10 /x diam. The original gathering on which Sommerfelt founded 



S. arcyrioides, of which through the courtesy of Prof. Blytt of Christi- 



ania a mounting is in the British Museum, has globose sporangia, 



with brown capillitium and nearly smooth spores 8 to 9 /x diam., as in 



typical L. violaceum. The measurement " 12 - 5 to 16"5 xi " given by 



Rostafinski and repeated in other works is erroneous, but is corrected 



by Prof. Blytt, I.e. By the strict application of the rule of priority, 



the name L. arcyriodes should take precedence of L. violaceum, but the 



former has been so long associated with a misleading description that 



it would seem preferable to retain the familiar and appropriate name 



given by Fries. The typo of L. Sauteri from Salzburg in the Tyrol, 



now in the Strassburg Herbarium, has the same form of sporangium 



and abundant brown capillitium as in the type of S. arcyrioides Somm., 



but has spinulose spores, 11 to 14 p- diam. The type of Lampro- 



derma robustum Ellis and Everh., from Philadelphia (B.M. slide), is 



var. Sauteri with dark, strongly spinulose spores 11 to 13 /x diam. ; it is 



almost identical with the type of L. Sauteri. In some gatherings of var. 



Carestiae the spores measure 9 /x, in others 11 to 14 \x, in others again 



14 to 17 /x ; they are usually dark purplish-brown, and either nearly 



smooth or strongly spinulose. The var. dictyosporum is distinguished 



l2 



