448 Bulletin 315 



in diameter. Zygospores measure 120-140/i with maximum i8o/i, variable 

 in form, being round, oval, or without any particular form. Suspensors 

 equal or different in form and in size. (Description after Lendner.) 



Hab. Glacial sediment, altitude 3,000 m., Switzerland, Lendner; tilled 

 soil, Christiania, Norway, Hagem. 



Hagem considers his M. nodosus and Namyslowski's R. nodosus as 

 synonymous, while his M. Norvegicus is claimed to be a new species. On 

 the other hand, Lendner considers all three species as identical. The 

 cultures have not been studied by the writer. 



Rhizopus arrhizus Fischer, Rab. Krypt. Flora Abt. 4, i : 233-234. 1892. 

 Hagem, Untersuch. u. Norw. Mucorineen i: 37-38. fig. 14. 1907. 

 Lendner, Les Mucorinees de la Suisse, 121-122. fig. 44. 1908. 



Differs from R. nigricans in being brighter-colored and not spreading 

 so far over the substratum, also in the stolons being less distinct and less 

 differentiated from the sporangiophores ; stolons without distinct formation 

 of nodes, with colorless or bright brown membrane ; rhizoids pale, developed 

 at the nodes together with the sporangiophores or alone at indeterminate 

 places; sporangiophores ascending or trailing, seldom arising from the 

 stolons singly but mostly 2-10 in umbels or corymbs, 0.5-2 mm. long, 

 simple or once or twice forked, ending in sporangia; sporangia globose, 

 large, 120-250JU in diameter, at first snow-white then finally becoming at 

 maturity black; columella spherical, flattened on the apophysis, 40-7 5/x 

 high by 60-ioo/i thick, with brown , smooth membrane ; spores globose or 

 oval, one- or two-angled, with longitudinally striated membrane, 4.8-7/* 

 long by 4.8-5.6iu thick, smoky gray. (Description after Fischer.) 



Hab. Isolated from soil, Hungary, Namyslowski. 



Mucor 



I. Sporangiophores unb ranched Mono-mucor 



IL Sporangiophores branched 



1. Branching rare or more frequent, and in this latter case indefi- 



nite, in clusters or in corymbs Racemo-mucor 



2. Branching definite, in sympodia Cymo-mucor 



Mono-mucor 



Sporangiophores not branched (exception, when the nutrition is un- 

 favorable, branching occurs; this, however, is anomalous). 



1 . Sporangiophores not exceeding 2 centimeters in length 2 



Sporangiophores more than 2 centinieters long 3 



2. Sporangia red, 20-3 5/x, with diffluent membrane, spores 2.5 



by 2/i M. Ramannianus Moller 



