TWO >EW VAHIETJES OF LA MPKUDKiniA 27 



The latter species in its typical form has large globose or ovoid 

 glossy black sporangia, short stalks, dense black capillitium attached 

 by the tips of the threads to the sporangium- wall, which breaks away 

 ultimately" in small f i-agments ; the purplish-black spores measure 

 13 to 16 yu, and are either spinose, spinulose, or closely reticulated*. 



Form B resembles L. atrosporum in having the capillitium 

 attached to the sporangimn-wall and in the closely reticulated spores, 

 and diifers chiefly in its more slender habit ; we propose to include it 

 under that species, distinguishing it by the varietal name anc/Ucum 

 G. Lister & Howard. 



That the size and colour of the spores cannot be regarded as an 

 entirely reliable character is sho\vn by a gathering of L. atrosporum^ 

 found on the Weissenstein on earth and beech-leaves, close to the 

 sporting development of i. violaceum described above. In some of 

 the large black sporangia the spores are spinulose, very dark, and 10 

 to 13^ diam., in other sporangia they are 2^urplish-grey, 12 to 15 /z 

 diam., and spinose : in all the spores there is a tendency for the spines 

 to be connected by low ridges, the result being a very imperfect 

 reticulation. 



M. Meylan has recently published a new species, L. CrucJieti 

 (see " M\'xomycetes nouveaux " in Bull. Soc. Vaud. Sc. Nat. lii. 

 p. 95), found in Sej^t. 1915 on Chasseron, in the Jura Mountains, at 

 an altitude of 1100 m. It is allied, he writes, to L. columhinum 

 (Pers.) Eost., from which it differs in the smaller blackish-brown 

 sporangia, whose walls show no trace of iridescence, in the very 

 slender capillitium, and, above all, in the dull yellow almost ochi'aceous 

 colour of the plasmodium. 



It must be confessed that the genus Lamproderma still presents 

 many difficulties, and we have much to learn concerning the limita- 

 tions and variations of several of the species, and particularly of the 

 relation between alpine and lowland species in different countries. 



Explanation of Plate 552. 



1. Lamprodeitna violaceum, (Fries) Rost. var. dehile G. Lister & Howard. 



Sporangia on Beech-leaf. 



1 a. Sporangia of various shapes. 



1 6. Sporangium after dispersion of spores showing short columella and capil- 

 litium. 



1 c, Capillitium-threads and spores. 



1 d. Two spores. 



2. L. atrosporum Meylan var. angUcum G. Lister & Howard. Stalked and 



sessile sporangia on Box-leaf. 



2 a. Sporangium after dispersion of spores. 



2 h. Capillitium, showing the tips of the threads adhering to the sporangium - 



wall and spores. 

 2 c. Spores, shoAi\dng reticulated markings. 



* The form described as Larnproderma violaceum var. dictyosporum in the 

 British Museum Catalogue, ed. 2, p. 167, is included in L. atrosporum Meylan. 



