HEMITRIOHIA.J TEIOHIACE^. 175 



KEY TO THE SPECIES OF HEMITEIGHIA. 



A. Spores nearly smooth, or minutely warted : — 



A. Capillitium red, spinose. 1. H. rubiformis 



B. Capillitium yellow or yellow-brown — 



a. Sporangia stalked — 



Stalk soUd. 2. H. intorta 



Stalk hollow, fiUed with spore-like cells — 



Cup papillose. , 3. E. clavata 



Cup smooth. 4. H. leiooarpa 



b. Sporangia sessile — 



Spirals of capiUitium one to three, prominent, 

 sporangium-wall membranous. 



5. H. Wigandii 



Spirals of capiUitium three or more^ indistinct, 

 sporangium-wall thickened with granular 

 deposits. 6. H. Karstenii 



B. Spores reticulated : — 



Capillitium threads spinose. 7. H. Serpula 



Capillitium threads smooth. 8. H. chrysospora 



1. H.I rubiformis Lister. Plasmodium purple-red, in rotten 

 wood. Total height 1'3 to 2'5 mm. Sporangia clavate or sub- 

 cylindrical, stipitate or sessile, combined in clusters or crowded, 

 1 to I'S mm. high, 0'5 to 0'7 mm. broad, glossy or shining, dark 

 red, red-brown, or oHve-black ; sporangium-waU of two layers, the 

 outer contuiued into the stalk, the inner enclosing the spores, 

 orange-red. Stalks membranous, 0'2 to 1 mm. high, usually 

 combined in clusters of from six to twelve, furrowed and rugose, 

 red, not enclosing spore-like cells. OapilUtium of twisting, spar- 

 ingly branched, orange-red threads 5 to 6 /j, diam.,, marked with 

 three to five regular spiral bands, beset with numerous scattered 

 spines 2 to 5 /a long, rarely nearly smooth, with few pointed free ends. 

 Spores pale orange-red, warted, 10 to 11 /x, diam. — Hemiwrcyria 

 rubiformis Rost., Mon., p. 262 ; Cooke, Myx. Brit., p. 67, figs. 201, 

 230, 231 ; Blytt, Bidr. K. Norg., Sop. iii. (1892), p. 13; Macbride, 

 in Bull. Nat. Hist. Iowa, ii., p. 133. Trichia rubiformis Pers., 

 in Ebmer, N. Mag. Bot., i., p. 88 (1794). Arcyria rubiformis 

 Mass., Mon., p. 158. Trichia Neesiama Corda, Ic, i., p. 23. 



o. genuina : sporangia red-brown. 



j8. Neesiana Host. : sporangia oUve black. 



Pl,ate LXIII., A.— a., sporangia, x ,20; S. capillitium and spores, ■>< 280; 

 c. capillitium and spore, x 600 (England). 



Sporangia are occasionally found with a few free elaters pointed 

 at each end, in addition to the continuous network of threads of the 

 usual type. 



