OLIVE, — PRELIMINARY ENUMERATION OF THE SOROPHORE^E. 339 



On the dung of various animals, such as horse, rabbit, dog, guinea pig, 

 grouse, etc. Also found on cultures of yeast, paper, fleshy fungi, etc., in 

 a state of decomposition. Germany, Russia, common in America. 



This very common species is extremely variable in the size of its spores 

 and fructifications. The limits of the spore measurements as given by 

 Brefeld in his original description have been therefore somewhat 

 increased. 



Dictyostelium sphaerocephalum (Oud.) Sacc. and March. 

 {Hyalostilbum sphcerocepha/um Oudemans.) 



Aauw. Myc. Nederl., IX.-X. p. 39. PI. IV. 1885. 



Sorus white ; when old, yellowish or greenish-white. Stalk frequently 

 very long and luxuriant, varying from 2 mm. to 1.5 cm. Spores oval, 

 rarely spherical, or sub-inequilateral, Sfi-5p. X O/a-IO/^. 



Dung of mouse, (common), rat, bird, toad, deer, turtle, muskrat, etc. 

 Belgium ; Cambridge and Boston, Mass. ; New Hampshire ; Florida ; 

 Pennsylvania ; Liberia. 



In the above description the limits of the measurements of spores and 

 of the length of stalks are greater than those given by Marchal, by 

 whom the maximum length of the spore is stated as S^w and that of the 

 stalk as 5mm. The measurements of the fructifications are certainly 

 more variable than indicated by Oudemans. This species was founded 

 by Marchal from the fact that the spores differed in size from those of 

 Dictyostelium mucoroides, which he states to be only about one-half as 

 large. As will be seen by the measurements given above, this difference 

 is by no means as great as indicated ; and, although the present arrange- 

 ment is retained for the present, it may prove desirable to unite these 

 two variable species. 



Dictyostelium roseum Van Tieghem. 

 Bull, de la Soc. Bot. de France, XXVIL p. 317. 1880. 



" Spore mass spherical, of a bright rose color. Spores elongated oval, 

 4,u. X 8/i. On the dung of various animals ; especially on rabbit dung, 

 in company with Pilobolus microsporus." France. 



Dictyostelium lacteum Van Tieghem. 

 Bull, de la Soc. Bot. de France, XXVIL p. 317. 1880. 



"The mass of spores forms a milk-white drop at the summit of a stalk 

 which I have always seen composed of a single row of cells. Spores 



