168 A Monograph of the Myxogastres. 



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The stipitate sporangia and elastically protruded capillitium 

 attached at the base, as also the spiral markings on the threads 

 prove the present species to be an Arcyria, in which genus 

 free arms to the capillitium are frequent in several species. 



Arcyria Karsteni, Host. 



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 p. 

 thick, with scattered, inflated portions 12 15 p thick, and 

 30 50 p long, spirals very indistinct, a few scattered rudimentary 

 spines now and then present, free tips not distinctly attenuated, 

 usually abrupt or clavate; spores globose, smooth, 12 12 /x 

 diameter. 



Hemiarcyria Karsteni, Host., Mon. Suppl., p. 41 ; Karst., 

 Myx. Fenn., iv., p. 142; Schroeter, p. 115; Sacc., Syll., vii., 1, 

 n. 1510 ; Mass., Rev. Trich., p. 342, fig. 36. 

 (Specimen from Ceylon in Herb. Berk., named by Rostafinski.) 



On wood. Finland ; Silesia ; Ceylon. 



Characterized by the threads of the scanty capillitium being 

 considerably swollen at intervals, and by the indistinct spirals. 



Arcyria pusilla, Mass. 



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 Hood-red with an amber tinge, 

 afterwards rose-colour ; capillitium rather dense, forming a rose- 

 coloured network, threads round, 3 4 fx thick, spirals three or 

 four, furnished with minute spinules ; spores rose or flesh-colour, 

 globose, smooth, 7 9 ^t diameter. 



H&mitrichia pusilla, Speg., Fung. Arg. Pug., IV., n. 260. 



Hemiarcyria pusilla, Berldfee, Sacc., Syll., IV., 1, n. 1512; 

 Mass., Rev. Trich., p. 352. 



On bark. . Argentine Republic. 



