slender tubules forming a loose net-work, more or less
expanded at the angles and for the most part filled with lime; the
nodules white, slender, much elongated and branched, with pointed lobes
and branchlets. Spores globose, very minutely warted, dark violaceous,
11-13 mic. in diameter.

Growing on old stalks of _Zea mays_. Sporangium .5-.6 mm. in diameter,
the stipe about twice this length. The lower part of the capillitium is
sometimes entirely filled with lime, so that the species approaches
Badhamia in the structure of its capillitium.

18. PHYSARUM LEUCOPUS, Link. Sporangium globose, the base slightly
flattened, stipitate; the wall a thin, violaceous membrane, with a
white, pulverulent outer coat of minute granules of lime. Stipe short,
thick, erect, snow-white, longitudinally rugulose, tapering upward,
expanding at the base into small, white hypothallus. Capillitium a loose
net-work of tubules, with wide expansions at the angles; the nodules of
lime large, white, numerous, irregularly lobed and branched. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter.

Growing on old wood, leaves, etc. Sporangium .3-.4 mm. in diameter, the
stipe about the same length as the diameter. Our specimens are a smaller
form than the European, with smaller and smoother spores. Superficially
the species resembles _Didymium squamulosum_, and it is _Didymium
leucopus_ of Fries, S. M.

19. PHYSARUM GLAUCUM, Phillips. Sporangium globose, or the base slightly
depressed, stipitate; the wall a thin, violaceous membrane, covered with
minute, white granules and small roundish or irregular scales of lime.
Stipe short, stout, erect, black, longitudinally wrinkled, expanding at
the base into a small hypothallus. Capillitium of much-flattened
tubules, forming a loose net-work, widely expanded at the angles; the
nodules of lime numerous, large, white, irregular, with pointed angles
and lobes. Spores globose, very minutely warted, dark violaceous, 12-14
mic. in diameter.

Growing on old leaves: California. Sporangium .5-.7 mm. in diameter,
the stipe not longer than the diameter. This is quite a robust species,
both externally and in the broad, flat tubules of the capillitium.

20. PHYSARUM RELATUM, Morgan, n. sp. Sporangium globose, the base
umbilicate, stipitate, often cernuous; the wall a thin, violaceous
membrane, rugulose and iridescent, covered with small, roundish or
irregular white scales of lime. Stipe long, erect