ous columella and the non-calcareous capillitium. On the other
hand the structure of the capillitium and the iridescent simple peridium
ally _Diachaea_ to _Lamproderma_ and the _Stemoniteae_; the only
distinction being the calcareous stem. It is simply an intermediate
genus to be placed here more conveniently than anywhere else in what is
of necessity a linear arrangement.

=Key to the Species of Diachaea=

_A._ Stipe and columella white.

_a._ Sporangium cylindric 1. _D. leucopodia_

_b._ Sporangium globose.

i. Evidently stalked 2. _D. splendens_

ii. Stalk very short, 5 mm., conic.

O Spores warted 3. _D. bulbillosa_

OO Spores faintly netted 4. _D. subsessilis_

_B._ Stipe yellowish or orange 5. _D. thomasii_

1. DIACHAEA LEUCOPODIA (_Bull._) _Rost._

1791. _Trichia leucopodia_ Bull., _Champ. de la France_, Pl. 502,
Fig. 2.
1825. _Diachaea elegans_ Fries, _Syst. Orb. Veg._, I., p. 143.
1875. _Diachaea leucopoda_ (Bull.) Rost., _Mon._, p. 190.

Sporangia rather closely gregarious, metallic blue or purple iridescent,
cylindric or ellipsoidal, obtuse, sub-umbilicate below, stipitate; stipe
short, much less than one-half the total height, snow-white, tapering
upward; hypothallus white, venulose, occurring from stipe to stipe to
form an open network over the substratum; columella thick, cylindric,
tapering, blunt, terminating below the apex, white; capillitium
springing from every part of the columella, of slender threads, brown,
flexuous, branching and anastomosing to form an intricate net; spores in
mass nearly black, by transmitted light dull violaceous, minutely
roughened, 7-9 mu.

A very beautiful species; not uncommon in the eastern states; rare west
of the Mississippi. Easily recognized, amid related forms, by its
snow-white stem, a feature which did not escape the notice of Bulliard
and suggested the accepted specific name. Fries adopted the specific
name proposed by Trentepohl and wrote _D. elegans_, simply because to
him the peridium was "admodum elegans."

The peridium is exceedingly thin and early deciduous; the stipe long
persistent. The plasmodium, dull white, was observed by Fries at the
beginning of the century; "morphoseos clavem inter myxogastres hoc genus
primum mihi subministravit."

This species