DIANEMA 239 



2. DiANEMA CORTICATUM List. 



Plate XVI., Figs. S a, S c. 

 1894. Dianema corticatum List., Mycetozoa, p. 205. 



"Plasmodium pink"; sporangia sometimes flat-hemispheric, more 

 often ill-defined, united in irregular, depressed, netted plasmodio- 

 carps, generally dull brown ; peridium opaque, didermatous, capilli- 

 tium of simple or rarely branching filaments, variously beaded or 

 marked with spiral bands, lightly attached at either end, occasionally 

 twisted together; spore-mass dull brown, the spores in clusters of 

 four or more, colorless by transmitted light, more or less verruculose, 

 ellipsoidal, about 8-10 /m. 



Our specimens are from the mountains of Alberta. 



A curious, flat plasmodiocarp, an inch or more in length. It sug- 

 gests Hemitrichia serpula prematurely dry. 



3. Dianema andersoni, Morg. 



Dianema andersoni, Morg. MS., non. pub. 



Sporangium globose, sessile or substipitate, seated on a thin brown- 

 ish hypothallus ; the wall a thin smooth pinkish membrane, when dry 

 rugulose and iridescent, the inner surface somewhat thickened below 

 and brownish at the base. Capillitium arising out of the thickened 

 base, the threads hyaline or pinkish, ascending, flexuous, simple, or 

 branched a time or two, the extremities attached on all sides to the 

 wall of the sporangium. Spores globose, very minutely warted, pale, 

 pinkish, 10-11 yu, in diameter, free. 



Growing on old wood and bark of Alnus; British Columbia, 

 W. B. Anderson. 



Sporangium spherical, 6-8 mm. in diameter, sessile or on a very 

 short stipe. This species differs from D. harveyi Rex in the uniform 

 pinkish color of the wall and of the spores; the dividing threads 

 are furnished remotely with minute roundish tubercles as in Didy- 

 mium; the spores are somewhat larger than in D. harveyi. 



B. PERICHi^NACE.^ 



Key to the Genera of the Perichsenaceaa 



A. Sporangia more or less plasmodiocarpous in type, terete; dehiscence 

 irregular 1. Ophiotheca 



