260 THE NORTH AMERICAN SLIME-MOULDS 



1. Free ends more or less abundant, 



8. H. clavata 



2. Free ends none . . . 9. //. stipitata 



* Stalk solid 7. H. intorta 



ii. Not yellow. 



* Ruby red 4. //. •vesparium 



** Copper-colored 5. //. stipata 



1. Hemitrichia serf u la (Scop.) Rost. 



Plate III., Figs. 4, 4 a, 4 b. 



1772. Mucor serpula Scop., FL Carn, II., p. 493. 



1794. Trichia serpula (Scop.) Pers., Rom. N. Bot. Mag., I., p. 90 



1875. Hemiarcyria serpula (Scop.) Rost., Mon., p. 266. 



Fructification plasmodiocarpous, often covering several square centi- 

 metres, terete, branching freely and usually everywhere reticulate, 

 rusty, tawny, or bright yellow ; the peridium thin, transparent, with 

 irregular dehiscence; hypothallus none; capillitium variable, a tangle 

 of long yellow threads, sparingly branched, free everywhere, except be- 

 low, spinulose, the free tips spinose, acuminate, spiral ridges three or 

 four, with traces of longitudinal strise; spore-mass golden yellow, 

 spores beneath the lens pale yellow, globose, delicately reticulate, 

 about 10 /x. 



Very common, recognized by its bright yellow color and conspic- 

 uous reticulate habit. The Plasmodium is yellow, at least upon emer- 

 gence, and passes almost without change to fruit. Found on rotten 

 logs of every description, on the lower surface. In the Mississippi 

 valley, the lower surface of planks used in the construction of side- 

 walks appears to be a favorite habitat. 



Common west to the Rocky Mountains, south to Mexico and Nic- 

 aragua. 



2. Hemitrichia karstenii {Rost.) List. 



1876. Hemiarcyria karstenii Rost., Mon., App., p. 41. 

 1891. Hemiarcyria obscura Rex, Proc. Phil. Acad., p. 395. 

 1894. Hemitrichia karstenii Lister, Mycetozoa, p. 178. 



Fructification plasmodiocarpous, with a tendency to form distinct 

 sessile, globose sporangia, color brownish red ; capillitium a sparingly 

 branched network, with free ends few, the thread marked by 



