508 PKOCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
The fact that fructifications seemingly similar in all respects to-. 
those of Dictyostelium may occasionally be formed (pi. 8, fig. 118, 
a), especially on van Tieghem cell cultures, together with the fact 
that the stalks and spores of the two are alike in general structure,, 
indicates that Polysphondylium and Dictyostelium are very closely 
related to each other. It is possible that the distinction is not great 
enough to warrant the retention of the two forms as distinct genera. 
Yet the almost constant character seen in Polysphondylium involv¬ 
ing the bearing of whorls of branches all of about equal length,, 
indicates that the two organisms possess important physiological as 
well as structural differences. 
Polysphondylium violaceum Brefeld. Plate 8, fig. 112-118» 
Schimmelpilze, bd. 6, p. 3-34, pi, 1-2, 1884. 
Sori and stalks purplish or dark violet, varying in height from 
about J cm. to 2 cm.; sori about 50 /x-300 in diameter. Spores 
elongated oval, 2.5 /x by 6 /x-8 fx. 
On dung of horse, bird, sheep, toad, muskrat. Italy ; Maine 
New Hampshire; Massachusetts; Florida. 
The limits of spore measurement as given by Brefeld have been 
increased here as in other instances. The form growing on bird 
dung, brought by Prof. F. O. Grover from Center Ossipee, N. H., 
and the Massachusetts form on the dung of muskrat, seem to corre¬ 
spond very closely to the type description. The spores of the Maine 
and Florida forms are somewhat smaller, while the general aspect of 
the fructifications is different in that they are more delicate and less 
luxuriant and the sori have a less diameter than do those of the type. 
These differences, however, seem hardly more than varietal. 
Polysphondylium pallidum Olive. Plate 8, fig. 119-120. 
Proc. Amer. acad. arts and sci., vol. 37, p. 342, 1901. 
Sori and stalks white, the sori about 50 /x-80 /x in diameter. 
Spores oval, 2.5 /x-3 /x by 5 /x-6.5 /x ; or occasionally spherical, about 
7 /X—8 /X in diameter. 
On dung of ass, rabbit, muskrat. Liberia, Africa; Arlington and 
Stony Brook, Mass. 
