let, 7-8 mu.

We here recover as is believed one of Rostafinski's best-described
species. Our material is from Nicaragua, by kindness of Professor
Shimek. Its relationship is with _S. fusca_ where Rostafinski placed it.
The phrase describing spore-color is his.

6. STEMONITIS NIGRESCENS _Rex._

1891. _Stemonitis nigrescens_ Rex, _Proc. Phil. Acad._, p. 392.
1911. _Stemonitis fusca_ Roth, Lister, _Mycetozoa, 2nd ed._, p. 143.

Sporangia gregarious, upon a common hypothallus, erect, small,
cylindric, stipitate; stipe black, extremely short, about half a
millimetre; columella reaching the apex; capillitium violet-black,
darker near the surface, forming a complete superficial net at the lower
part of the sporangium only, elsewhere irregular or vanishing;
spore-mass nearly black; single spores violet-black under the lens, the
epispore spinulose and reticulate, about 8 mu.

The author of this species remarks: "This species is noteworthy for its
comparatively short stipes, its very spinulose spores, and its black or
nearly black color, the slight violet tint being only apparent on close
inspection, especially in fresh moist specimens."

It is a small but very beautiful form, at first sight to be mistaken for
a short _S. fusca_, though much more intensely black. The capillitium is
concolorous, the inner network of rather few open meshes, the outer of
large hexagonal openings, the arcuate threads of which are remarkable
for the size, and especially the number, of the peridial processes, as
many as five or six sometimes appearing along one side of a single mesh.
The stipe is very short, and the columella runs as a straight, gradually
diminishing axis to the very apex of the sporangium. Total height 3-5
mm.

The English _Monograph_ includes this with _S. fusca_; but it seems
quite distinct in size, habit, color, etc., and has been found in the
mountainous regions of Virginia and North Carolina, as well as about
Philadelphia.

7. STEMONITIS VIRGINIENSIS _Rex._

1891. _Stemonitis virginiensis_ Rex, _Proc. Phil. Acad._, p. 391.
1899. _Stemonitis virginiensis_ Rex, Macbr., _N. A. S._, p. 130.
1911. _Comatricha typhoides_ Rost., List., _Mycetozoa, 2nd ed._,
p. 158.

Sporangia erect, gregarious, from a common hypothallus, generally
clustered, cylindric or elongate-ovate, stipitate; stipe black, shining;
columella reaching the apex, where it blends with the capillitium;
capillitium delicate, the me