190 THE JOURNAL OF BOTANY 



loped spongy hypothallus; sporangium-wall membranous, 

 beset with microscopic dark plasmodic granules. 



Sporangia forming an sethalium . . . L. Tubulina Fries 



Sporangia closely compacted, sessile, or shortly stalked 



L. Tubulina var. simplex Eex 



25. Cribraria Persoon. Sporangia globose, stalked ; sporangium- 



wali persistent and usually forming a cup in the lower half, 

 continued above as a net of slender threads more or less 

 thickened at the nodes, evanescent in the meshes; spores 

 nearly smooth. 



A. Nodes of the net not thickened : 



a. Sporangia clay-coloured, cup imperfectly defined, sporangium- 



wall subpersistent above . . • C. argillacea Pers. 



b. Sporangia red, net close O. rubiginosa Fr. 



c. Sporangia nut-brown or rufous — 



Sporangia 0*6 mm. diam., net lax . C. rufescens Pers. 



Sporangia 0-1 to 0*2 mm. diam . C. minutissima Schw. 



B. Nodes of net thickened : 



a. Sporangia nut-brown 

 a. Cup ribbed, perforated at the margin, merging into the 



branching nodes C. maeroearpa Schrad. 



(3. Cup well-defined, nodes flattened, angular, branching 



C. aurantiaca Schrad. 



y. Cup replaced by strong ribs ; nodes flattened 



C. splendens Schrad. 



$. Cup well-defined or absent, nodes thickened, prominent, 



numerous — 

 Nodes with free rays, and connected by delicate threads, 

 many of which are parallel . . C. intricata Schrad. 



Nodes rounded in outline, without free rays, connected by 

 four to five delicate threads . . . C. tenella Schrad. 



b. Sporangia dark or red- brown 

 a. Stalk two or three times the height of the sporangium ; 



plasmodic granules dark, 1-2 [x diam. 



C. pyriformis Schrad. 



/?. Stalk four to six times the height of the sporangium 



Cup one-third the height of the sporangium, nodes polygonal 



O. languescens Rex 



Cup minute or absent, nodes rounded, prominent 



C. mieroearpa Pers. 



c. Sporangia purple 



Cup one-third the height of the sporangium, 0-7 mm. diam. 



C- purpurea Schrad. 



Cup one-half of the sporangium, 0'5 mm. diam. 



C. elegans Berk. & Curt. 



d. Sporangia violet-blue ; sporangia 0-25 mm. diam. 



C. violacea Rex 



