differently.

10. PHYSARUM DIDERMOIDES, Pers. Sporangia obovoid-oblong, stipitate,
growing close together on a white membranaceous common hypothallus; the
wall with a thick, white, outer layer of lime, easily crumbling and
falling away, leaving the sporangium dark gray; the inner membrane
rather thick and firm, violaceous, with a closely adherent layer of
granules of lime. Stipes very short, white, thin, and weak, each formed
by a bit of membrane arising from the hypothallus. Capillitium a loose
net-work of slender threads, bearing numerous roundish or irregular
white nodules of lime. Spores irregularly or angularly globose, minutely
warted, dark violaceous, 12-15 mic. in diameter.

Growing on wood, leaves, grass, etc. Sporangia .6-1.2 mm. in length by
.4-.6 mm. in thickness, the stipe shorter than the sporangia. _Spumaria
licheniformis_ Schw., belongs here. This is a truly abnormal species of
_Physarum_, so much so that Fries, in the _Summa Veg. Scand._ placed it
by itself in a separate genus, _Claustria_.

_B. Sporangia sessile._

11. PHYSARUM CONFLUENS, Pers. Plasmodiocarp roundish, oblong or
elongated, and by confluence branched and reticulate; the wall a thin,
violaceous membrane, rugulose, with a thin, closely adherent layer of
minute granules of lime, over which are scattered small, white, roundish
nodules, which sometimes accumulate into a thick, pulverulent coat.
Capillitium a loose net-work of tubules, widely expanded at the angles;
the nodules of lime small, white, very numerous, roundish or
ellipsoidal, by confluence elongated and irregular. Spores irregularly
globose, minutely warted, dark violaceous, 9-11 mic. in diameter.

Growing on old wood, bark, leaves, etc. Plasmodiocarp .4-.5 mm. in
thickness, varying from roundish to much elongated, creeping and
reticulate. The sporangium before dehiscence is gray, whence Link's
name, _Physarum griseum_; the loose pulverulent coating of lime easily
falls away, leaving the sporangium dark colored, whence Rostafinski's
name, _Physarum lividum_. The amount of lime on the wall and in the
capillitium is variable.

12. PHYSARUM LUTEOLUM, Peck. Sporangia small, subglobose, sessile,
closely gregarious; the wall a thin membrane, covered by a layer of
small scales of lime, yellowish, inclining to tawny, in color, rupturing
irregularly. Capillitium of slender tubules, forming a dense net-work of
small meshes, scarcely expanded at the angles; the nodules of lime
small,