HEMITKICHIA.] TRICHIACE^. 179 



marked with three to five indistinct spiral bands, often with 

 scattered ring-shaped thickenings and irregular expansions ; free 

 ends pointed or blunt. Spores yellow, minutely warted, 9 to 15 /x 

 diani. Hemiarcyria Karstenii Host., Mon., A pp., p. 41 (1876). 

 Arcyria Karstenii Mass., Mon., p. 168. Hemiarcyria paradoxa 

 Mass., in Journ. R. Micr. Soc. (1889), p. 356. Arcyria paradoxa 

 Mass., Mon., p. 160. Hemiarcyria obscura Rex, in Proc. Acad. 

 Nat. Sc. Phil. (1891), p. 395. 



Plate LXV., A. a. plasmodiocarp, x 20 ; b. portion of sporangium- wall, 

 showing the granular outer and membranous inner layers, x 280 ; <?. capilli- 

 tium and spores, x 280 ; d. capillitium, x 600 ; e. spore, x 600 (England). 



This species appears to be a Hemitrichia form of Trlchia contorta, 

 which it resembles in every respect, except that the capillitium threads 

 are combined instead of forming free elaters ; the same variety in 

 shape and colour of the sporangia, and in the markings and colour of 

 the capillitium, occur as in that species. Rostafinski's type specimen 

 from Ceylon (K. 1773) has pale yellow-brown sporangia and rugged 

 capillitium, with faint spirals and many large rounded expansions ; 

 the spores are yellow, minutely warted, and measure 10 to 11 p. diam. 

 Specimens from near Dudley, found by Mr. Camm, have both globose 

 and plasmodiocarp purple-brown sporangia and orange-brown capilli- 

 tium, strongly contrasting with the yellow spores. The type specimen 

 of Arcyria paradoxa Mass., from Weybridge( K. 132), closely resembles 

 the Ceylon gathering of H. Karskenii, only differing in the more 

 regular, less branched capillitium, with fewer expansions ; it must 

 therefore be included under that species. The mounting of Hemiar- 

 cyria obscura Rex, I.e. (L:B.M. 149), furnished by Dr. Rex, shows a dull 

 yellowish-red capillitium ; the threads are 2'5 to 3 p. thick, and are 

 marked with close faint spirals ; they have nearly the same colour- 

 as those of the Dudley specimen, but are more uniform, with incon- 

 spicuous swellings ; the spores are similar to those of the type of 

 H. Karstenii at Kew, and there appears to be no specific character to 

 separate it from that species. 



Hob. On dead leaves. Dudley, Stafford (L:B.M.149); Weybridge, 

 Surrey (K. 132) ; Ceylon (K. 1773) ; Montana, U.S.A. (L:B.M.149 

 slide}. 



7. H. Serpula Rost,, Versuch, p. 14 (1873). Plasmodium? 

 Sporangia forming elongated, winding, branched plasmodiocarps, 

 0'4 to 0*6 mm. wide, usually combined to form a close net, golden- 

 yellow ; sporangium- wall of two layers, yellow. Capillitium a 

 tangle of twisting, sparingly branched, yellow threads, 5 to 6 /u, 

 diam., marked with three to four well-defined regular spiral 

 bands 0*7 //, wide, with intervals of 1 to 2 /x, strongly 

 spinose ; longitudinal striae often distinct ; free ends pointed. 

 Spores yellow, reticulated with narrow bands, forming a net with 

 about nine meshes to the hemisphere, 10 to 12 /x diam. ; border 

 0'5 to 1 u wide. Hemiarcyria Serpula Rost., Mon., p. 266 (1875) ; 

 Cooke, Myx. Brit., p. 68, figs. 200, 227, 228 ; Macbride, in Bull. 

 Nat. Hist. Iowa, ii., p. 135. Mucor Serpula Scop., El. Carn., 

 Ed. 2, ii., p. 493 (1772). Trichia Serpula Pers., in RSmer, N. 

 Mag. Bot., i., p. 90 (1794). Arcyria /Serpula Mass., Mon., 

 p, 164. 



