Dictydium. 67 



angles in the network. Stem from 2 3 times as long as 

 sporangium. 



DICTYDIUM, Schrad. 



Wall of sporangium single; permanent rib-like thickened 

 portions radiating from base to apex and joined by numerous 

 thinner transverse bands; thinner portions of wall situated 

 between the ribs disappearing at maturity, or persistent at the 

 base and forming an imperforate calyculus ; columella and 

 capillitium absent. 



Dictydium, Schrad., Nov. Gen. PL, p. 11 ; Host., Mon., 

 p. 229 ; Cooke, Myx. Brit., p. 57 ; Sacc., Syll., p. 410 ; Zopf, 

 p. 140. 



The primary, vein-like, permanent portions of the sporangium 

 radiate from the base and converge at the apex without 

 becoming much broken up or distorted, although there is 

 usually an indication of a reticulate arrangement near the apex ; 

 these primary ribs are united laterally by straight, thinner 

 portions, hence the arrangement of the skeleton is into more 

 or less regular rectangular meshes. 



Distrib. Europe; N.America; S. America ; Ceylon ; Australia : 

 species 2. 



Dictydium cernuum, Nees. (f. 133). 



Sporangium globose, cernuous, more or less umbilicate at 

 the apex, reddish brown; stem elongated, slightly thinner 

 upwards, with a sharp curve near the apex, above which the 

 stem is hyaline and shrivelled at maturity; below the curve 

 dark brown, opaque, smooth, passing into a small hypothallus ; 

 calyculus small ; mass of spores purple brown ; spores globose, 

 smooth, 5 7 n diameter. 



Dictydium cernuum, Nees., Syst., f. 117; Host., Mon., p. 229, 

 figs. 17, 19, 22; Cooke, Myx. Brit., p. 57, figs. 17, 19, 22; 

 Sacc., Syll., no. 1401; Schroeter, p. 106; Raunk., p. 51, Tab. 

 ii. fig. 4. 



Dictydium cernuum, var. laxum, B. and C., Grev. 1873, p. 67. 



Exsicc Fuckel, Fung. Rhen., 1445 and 2099; Syd., Myc. 



