30 THE NORTH AMERICAN SLIME-MOULDS 



4. FULIGO INTERMEDIA Macbr. n. S. 



i^thalium two to three cm. in greatest diameter, .5-1 cm. thick, 

 covered with a thin, fragile, but not calcareous, greyish or brownish 

 cortex; the spore-mass grey or violaceous-grey, firm, not at all sooty, 

 the sporangia intricate, their walls more or less calcareous; capil- 

 litium not conspicuous; spores globose, pale purple, slightly rough- 

 ened, 10-12 fi. 



This form has been repeatedly sent me from Denver, Colorado, by 

 Professor Bethel. I have refrained from publishing it, still anxious 

 to believe that all fuligos on the face of the earth were of one species. 

 In the species next following it must be admitted that the spore- 

 variations are too wide to remain comfortably under shelter of a 

 single specific name. The present species is not F. septica, neither is 

 it F. rnegaspora; it is F. intermedia. 



Colorado ; Iowa. 



5. FULIGO MEGASPORA Sturg. 



1913. Fuligo rnegaspora Sturg., Col. Coll. Pub., p. 443. 



i?:^thalium pulvinate one to three inches in diameter, covered with 

 a thick spongy incrustation of lime, white or yellowish toward the 

 base: sporangia convolute, the walls membranous, brittle, charged 

 throughout with round white granules of lime, 1.5-2 ju, in diameter: 

 columella none: capillitium of delicate, colorless, anastomosing 

 tubules, bearing toward the center large, white, branching calcareous 

 nodules; spores spherical, or somewhat oval, dark purple-brown, 

 rough-tuberculate, 15-20 ju. 



This species differs as pointed out by Professor Sturgis, chiefly in 

 the character of the spores, their unusual size and roughness.^ 



Colorado ; Africa ! — Robert Fries. 



1 In discussing these species the reader may be referred to Professor 

 Harper's study of cytology, Bot. Gazelle, vol. XXX., p. 217. It is probable 

 that in all these sthalioid forms the effect of disturbance, transfer to labora- 

 tory, is likely to be quite pronounced. Giant spores are often seen, doubtless 

 due to arrested cleavage in the procedure described by Dr. Harper: a giant 

 spore is penultimate or antepenultimate in series; should, on this theory, occa- 

 sionally, at least, show more than one nucleus. 



