108 A Monograph of the Myxogastres. 



RACIBORSKIA, Berl. 



Sporangia naked, globose, stipitate, stem elongated, entering 

 the sporangium as a columella from one-third to half its height, 

 bearing at the apex secondary, short, slender columellas, these 

 in turn divide in a similar manner to the primary columella ; 

 ultimate branches combined amongst themselves at every point 

 to form a network ; extreme branchlets not free but arcuately 

 combined with each other. 



Hacibm'skia, Berlese, Sacc., Syll., vii., pt. I., p. 400. 



Eostafinslda, Racib., Myx. Crac., p. 9 (not of Spegazzini). 



Distrib. Poland. Species 1. 



Raciborskia elegans, Berl. 



Sporangia naked, globose, up to '5 mm. broad, stem erect, 

 1 2 mm. high, thickest at the base, then subulate-attenuated, 

 plicate, black ; columella half to one-third shorter than the 

 sporangium, cylindrical, 8 10 /u thick ; capillitium blackish- 

 violet, exterior threads exceedingly thin, not free ; the extreme 

 branches furnished with scattered spines; spores 9 10 JA 

 diameter, obscure violet, aculeate. 



Raciborslcia dcgans y Racib., Myx. Crac., p. 10, fig. 5. 



Poland. 



Raciborski considers that the present species is allied to 

 Rostafinski's genus Echinostclium. He also inclines to the idea 

 that tire genus Orthotricha may prove to be identical with his 

 Raciboi'slcm ( = Rostqfinskia y Racib.).* 



ECHINOSTELIUM, De Bary. 



Sporangia stipitate, columella absent, capillitium originating 

 from apex of stem, threads arcuate, combined to form a loose 

 network, furnished with numerous spine-like free arms. 



Echinostelium, De Bary, in Rost., Mon., p. 215; Cooke, Brit. 

 Myx., p. 53. 



* Hedwigia, March and April, 1889. 



