ection through the columella.
After Rostafinski.

Fig. 41.--Didymium anellus, Morgan, _a._ Growing upon a leaf x 3. _b._
Plasmodiocarp x 17.

Fig. 42.--Spumaria alba, Bull. Var. 1. didymium, sporangia x 3. Drawn
from a foreign specimen.

Fig. 43.--Spumaria alba, Bull. _a._ AEthalium natural size. _b._
Capillitium and spores as seen by a magnifying power of 500 diameters.

Fig. 44.--Diderma floriforme, Bull. Stipe and columella x 20.

Fig. 45.--Diderma crustaceum, Peck. _a._ Sporangia crowded on the thick
hypothallus, natural size. _b._ Sporangia x 11. _c._ Section through
outer coat, inner membrane, and columella.

Fig. 46.--Diderma cinereum, Morgan, _a._ Sporangia growing on a leaf x
3. _b._ Sporangia x 23. _c._ Section through the wall and columella.

Fig. 47.--Diderma reticulatum, Rost. Plasmodiocarp growing on leaf x 3.

Fig. 48.--Diderma effusum, Schw. Plasmodiocarp effused on a leaf x 3.

[Illustration: The Journal of the Cin. Soc. Natural History.

VOL. XVI. PLATE XII.]

* * * * *

Reprint from THE JOURNAL OF THE CINCINNATI SOCIETY OF NATURAL HISTORY,
August, 1896.

THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Fourth Paper.

(Read May 6, 1896.)

ORDER VIII. PHYSARACEAE.

Sporangia simple and stipitate or sessile, sometimes plasmodiocarp,
rarely combined into an aethalium; the wall a thin membrane, usually
with an outer layer of minute roundish granules of lime. Stipe present
or often wanting, seldom prolonged within the sporangium as a columella.
Capillitium consisting of slender tubules, which branch repeatedly in
every direction and anastomose to form an intricate network, the
extremities attached on all sides to the wall of the sporangium; the
tubules more or less expanded at the angles of the network and inclosing
minute roundish granules of lime, these granules either aggregated into
nodules with intervening empty spaces or more rarely distributed
throughout their entire length. Spores globose, very rarely ellipsoidal,
violaceous.

This order is at once distinguished from the Didymiaceae by the presence
of the granules of lime in the capillitium.

TABLE OF GENERA OF PHYSARACEAE.

I. Tubules of the capillitium having the granules of lime in them
aggregated into roundish or angular nodules, with intervening empty
spaces.

_A. Outer surface of the sporangium destitute of lime._

1. AN