Chondrioderma . 203 



narrow segments which leccnnc refiexcd ; columella white, minute ; 

 mass of spores blackish-purple; capillitium dense, threads 

 colourless, 2 — 3 /x thick, frequently forking at a wide angle, 

 and combined laterally to form a net, slightly thicker at the 

 point of bifurcation ; spores globose, itiimdcly vcrruculosc, 12 — 14 /x 

 diameter, 



LcmKjiitm? Trevclyani, Grev., Scot. Cr. Fl, pi. 132. 

 Chondrioderma Trcvclyana, Ilost.,Mon., p. 182, figs. 161—163 ; 

 Cooke, Brit. Myx., p. 40, figs. 161—163; Sacc, Syll., n. 1289. 



In the Appendix to Rostafinski's Monograph, the present 

 species is referred as a synonym to Chondrioderma radiatum. 



On living leaves of Brytim ligulatitm. Britain (Northumber- 

 land). 



Sporangia scattered ; 1—15 mm. diameter before dehiscence. 

 The above description is drawn up from a specimen originally 

 in Sowerby's Herbarium, and now in the Berkeley Herbarium, 

 Kew, and said to be from Greville. It is certainly quite 

 distinct from C. radiatum, in the greater number of segments 

 (14—16) into which the sporangial wall splits, the colourless 

 capillitium, and larger spores. 



(Rostafinski's Synonyms.) 



Leangium (?) Trevclyani, Grev., Scot. Cr. Fl., t. 132 (1825). 



Cionium Trevclyani, Spr., Syst., iv., 529 (1827). 



Didcrma Trevclyani, Fr., S. M., iii., 105 (1829); Eng. Fl., v., 



311 ; Cooke, Hdbk., No. 1111. 

 Polyschismium Trevclyani, Corda, Icon., v., p. 20 (1842). 



JB. Columella absent. 

 Chondrioderma Oerstedtii, Rost. (figs. 87, 88). 

 Sporangia stipitate, subglobose or broadly pyriform, when 

 mature sjjlitting in a stellate manner into 4 — 6 irregular, acute 

 segments, pallid ; stem short, usually darker than sporangium ; 

 columella entirely ahscnt ; threads of capillitium colourless or 

 dirty-lilac, combined to form a net, often furnished with darker 



