: The Myxomycetes of the Miami Valley Ohio by Morgan A P Andrew Price - Myxomycetes Ohio Miami River Valley

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upon a common hypothallus; the wall a thin membrane, minutely granulose, firm and quite persistent, gradually breaking away from the apex downward. Spores abundant, globose, umber or olivaceous.

Growing on old wood, mosses, etc. AEthalium circular or irregular in shape, from one to several centimeters in extent, the individual sporangia 2-4 mm. in height. Plasmodium at first milky-white, soon changing to bright red, then to umber, becoming paler when mature and dry.

If the sporophores in this genus be regarded as simple sporangia, which is the view that Rostafinski takes of one of the species, the tubules are simply the peculiar threads of a capillitium. If, however, the aethalium is a compound plasmodiocarp, the tubules stand for the original plasmodial strands and, consequently, represent the component sporangia.

Growing on old wood. AEthalium 2-5 mm. in diameter, the threads 2-10 mic. in thickness, with very slight thickenings of the membrane. The polygonal vesicles give a reticulate appearance to the dark-brown patches which ornament the surface of the wall.

Growing on old wood. AEthalium 5-12 mm. in diameter, the width of the tubules varying from 12-25 mic. in the main branches, with broader expansions at the angles, to 6-12 mic. in the more slender final branchlets. This is one of the most common of the Myxomycetes; it grows in all countries, and in this region may be found on old trunks at all seasons of the year.

Growing on old trunks. AEthalium 1 to several centimeters in diameter, the width of the tubules varying from 25-60 mic. in the main branches, with sometimes much broader expansions at the angles, to 10-25 mic. in the ultimate branchlets. The brown vesicles of the outer wall are easily separated from each other and emptied of their contents by maceration; it is then seen that a thin pellucid membrane incloses numerous roundish granules, much resembling the spores, but usually a little larger, 5-8 mic. in diameter.

Sporangia simple, regular and stipitate, or compound, forming an aethalium; the wall a thin membrane with distinct fibrous thickenings upon the inner surface, the membrane, or at least certain portions of it, disappearing usually at the maturity of the spores, leaving behind the more permanent fibrous thickenings as a more or less definite capillitium. Spores globose, purple, brown, ochraceous, rarely violaceous.

In this order the threads of a capillitium first make their appearance; but they are confined to the inner surface of the wall of the sporangium, being set at liberty by the early decay of the outer membrane.

TABLE OF GENERA OF RETICULARIACEAE.

After the maturity of the spores disintegration of the sporangial wall begins, the thin membrane disappearing more rapidly than the fibrous thickenings or the portions of the sporangial walls near the base, which are more compactly grown together; there is thus left at each stage an increasing number of the shreddy fibers mingled with the spores.

Growing on old wood. Sporangium .5-.7 mm. in diameter, the stipe two or three times the diameter of the sporangium in length. Recognized by the large sporangium and the very small nodules with their few radiating threads.

Growing on old wood. Sporangium .22-.27 mm. in diameter, the stipes 1-2 mm. in length. Readily distinguished by its very small sporangium and the comparatively very long stem. I am indebted to Dr. George A. Rex for specimens of this species.

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