82 THE NORTH AMERICAN SLIME-MOULDS 



state and station of its own ; our cwicern in European nomenclature, 

 in the present instance, almost disappears, and we return to our 

 synonymy from this side of the sea. 



Mr. Lister would recur to Dr. Peck's Didymium connatum, which 

 indeed represents the present species. In such disposition, how gladly 

 would all concur, were the thing possible ! But Physarum connatum 

 is already a synonym twice over.^ Unless we are done with the rules 

 entirely, P. connatum cannot stand. P. polymorphum and P. leu- 

 cophaeum are names already in use, of course ; and so under the cir- 

 cumstances, much as it is to be regretted, there would seem nothing 

 left to do but to cancel all past synonymy and impose a new name 

 whose permanence may at least be hoped for, if not expected. 



40. Physarum tropicale Macbr. 

 1899. Physarum tropicale Macbr., N. A. S., p. 45. 

 Plate XV., Figs. 4, 4 a, 4 h. 



Sporangia scattered, gregarious, turbinate, short stipitate, blue-gray, 

 about 1 mm. in diameter; peridium above iridescent, green, blue, etc., 

 dotted with minute flecks of white, below lime-less, purple or bronze 

 shading to the brown of the stipe; stipe short, stout, slightly rugose, 

 cylindric, non-calcareous, brown ; columella none ; hypothallus none ; 

 capillitium abundant, the nodes generally calcareous, small, uniform, 

 angular, white, uniformly distributed ; spore-mass, black ; spores dark 

 violet-brown, distinctly and closely warted, 12-15 ix. 



A large handsome species recognizable by the peculiar turbinate 

 sporangium, with its iridescent peridial wall in which green strongly 

 predominates above, bronze below. The distinction between the 

 upper and lower peridium w^ould suggest Craterium, but the internal 

 structure is not at all Craterium-like. The capillitium is typically of 

 Physarum. The color suggests P. leucophaeum violascens Rost. 

 From this species it is at once distinguished by its much longer spo- 

 rangia, larger and rougher spores. 



Mexico ; C. L. Smith : Sure to be again collected once that un- 

 happy country shall again open its forests to research. 



1 See Fries, Syst. Myc, Vol. III., pp. 130, 137, Rost, Mon., p. 127, and Rep. 

 N. Y. State Mus., XXXI., p. 55. 



