la none, capillitium dense, snow-white, with minute,
white, round or rounded nodes, in the centre a conspicuous mass of lime
forming a shining ball, not part of the stipe although sometimes
produced toward it; spore-mass black; spores brown-violet, delicately
spinulose, 6-7 mu.

This species most nearly resembles in appearance and habit of growth _P.
globuliferum_ Pers., but may be distinguished from it by the absence of
a columella, by the central ball of lime, and the very small rounded
lime-granules in the meshes of the capillitium. Exceptionally the lime
granules of the sporangium wall are sparse or absent entirely, in which
case the wall has a silvery or coppery metallic lustre.

Pennsylvania, Nicaragua.

29. PHYSARUM WINGATENSE _nom. nov._

PLATE XVI., Figs. 3, and 9.

1876. _Tilmadoche columbina_ (Berk. & C.) Rost., _Mon., App._,
p. 13 (?).
1889. _Tilmadoche compacta_ Wing., _Proc. Acad. Nat. Sci._, p. 48.
1894. _Physarum compactum_ List., _Mycetozoa_, p. 45.
1896. _Physarum compactum_ (Wing.) Morg., _Jour. Cin. Soc._, p. 91.
1899. _Tilmadoche compacta_ Wing., Macbr., _N. A. S._, p. 61.
1916. _Physarum columbinum_ (Rost.) Sturg., _Mycologia_, Vol. VIII.,
p. 4.

Sporangia gregarious, or somewhat crowded, erect or cernuous, stipitate,
gray or brownish gray, globose; peridium thin, metallic brown or bronze
in color, splitting at maturity in floriform manner into six to twelve
segments; stipe white or yellowish white, often shading to black or
fuscous below, rather long, tapering upward; hypothallus none; columella
none; capillitium extremely delicate, white or colorless, radiating from
a central lime-mass or nucleus, and with ordinary nodules small and few,
fusiform; spore-mass brown; spores by transmitted light, violet-brown,
delicately warted, 7-8 mu.

This species is well marked by several characteristics; the brilliant
wall of the peridium, white-flecked and laciniate, the delicate
_Didymium_-like capillitium running from centre to peridium, and
especially the peculiar aggregation of lime at the center of the
sporangium, like nothing else except a similar structure found in
_Physarum nucleatum_ Rex. The variations affect the stipe and the
distribution of the capillitial lime. Some eastern specimens show stipes
melanopodous, black below; specimens from Ohio and Nicaragua show stipes
milk-white throughout. As to the capillitium, in some of the Nicaragua
collections t