352 Transaciions of the Society. 



doubtful whether the above distinction is of generic value, as the 

 spiral arrangement is very evident in many species of Arcyria where 

 the spines or half-rings are arranged in a very open spiral, while in 

 Remiarcyria melanojoeziza the spirals are very rudimentary, but yet 

 present, whereas the threads bristle all over with long slender 

 spines. 



The thirteen known species are distributed as follows : — Europe, 

 seven ; United States, two ; South America, three ; Java, one. Some 

 of the European species extend to Africa, Ceylon, Australia, and New 

 Zealand. 



' A. Scores smooth. 



Hemiarcyria Karsfeni, Eost., fig. 36. 



Sporangia effused, vermiform, sinuous, sometimes forming irregular 

 reticulations, or hemispherical, scattered, and sessile on a broad base, 

 varying from dirty ochraceous brown to dark chestnut ; mass of 

 capillitium and spores dingy ochre ; threads often irregularly branched 

 and forming a very loose net, 3-4 /x thick, with scattered inflated 

 portions 12-15 /a thick and 30-50 fx long, spirals very indistinct, a 

 lew scattered rudimentary spines now and then present, free tips not 

 distinctly attenuated, usually abrupt or clavate ; spores globose, smooth, 

 10-12 /x diameter. 



Host., Mon. Suppl., p. 41; Karst., Myx. Fenn., iv. p. 142; 

 Schroeter, p. 115 ; Sacc, Syll, n, 1516. (Specimen from Ceylon in 

 Herb. Berk., n. 10,893, named by Kostafinski.) 



On wood. Finland, Silesia, Ceylon ! 



Kecognized by the threads of the scanty capillitium being con- 

 siderably swollen at intervals, and by the indistinct spirals. 



Hemiarcyria pusilla, Berlese. 



Sporangia rather closely gregarious, subcylindrico - elliptical, 

 0°4-0"5 mm. high, 0' 15-0 "25 mm. diameter, rather obtuse above, 

 abruptly subtruncate below with only a trace of a stem or altogether 

 without ; at first hlood-red with an amber tinge, afterwards rose- 

 colour ; capillitium rather dense, forming a rose-coloured network, 

 threads round, 3-4 /a thick, spirals three or four, furnished with 

 minute spinules ; spores rose or flesh-colour, globose, smooth, 7-9 /x 

 diameter. 



Berlese in Sacc, Syll., n. 1521. 



Eemitrichia pusilla, Speg., Fung. Argent., Pug. IV., n. 269. 



On bark. Argentine Eepublic. 



Hemiarcyria leiocarpa, Cooke, fig. 33. 



Sporangia scattered or aggregated, obovate or pyriform, rarely 

 almost globose, pallid, stem same colour, as long as diameter of 

 sporangia ; mass of spores and capillitium concolorous, or with a 

 slight ochraceous tint ; capillitium sparse, forming a loose net, threads 

 5-6 ju, thick, spirals thin, rather close, slightly prominent on the 



