gia produced by one plasmodium is in Iowa also small. The
larger specimens might be mistaken for species of _Perichaena_, but are
easily distinguished by the regular and lobate dehiscence. The
plasmodium is yellow.

Dr. George Rex, in almost the last paper from his hand, gives an
interesting account of this diminutive species. Among various gatherings
studied he found a black variety, a melanistic phase, so to say, and was
able to follow the evolution of the sporangia from the yellow
plasmodium. The sutures by which the peridium opens, first show signs of
differentiation by change of color from yellow through garnet to black.
Later the entire wall undergoes similar color changes, beginning next
the completed sutural delimitations. Of the open peridia, the reflexed
segments remind one of certain didermas, as _D. radiatum_. See _Bot.
Gaz._, Vol. XIX., p. 399.

New England, New York, Pennsylvania, Iowa.

4. LICEA PUSILLA _Schrader._

1797. _Licea pusilla_ Schrad., _Nov. Gen. Pl._, p. 19, tab. VI.,
f. 4.
1829. _Physarum licea_ Fries, _Syst. Myc._, III., p. 143.
1875. _Protoderma pusilla_ (Schrader) Rost., _Mon._, p 90.

Sporangia scattered, gregarious, depressed-globose, sessile on a
flattened base, dark brown, shining, .5-1 mm.; peridium thin, dark
colored, translucent, dehiscent above by regular segments; spore-mass
almost black, spores by transmitted light olivaceous brown, smooth, or
nearly so, 15-17 mu.

Fries, _l. c._, makes this a physarum, and argues the case at length,
evidently with such efficiency that he greatly impressed Rostafinski,
who did not make it a physarum indeed, but actually gave it generic
place and station of its own; a physarum may do without calcium in the
capillitium perhaps, but not be entirely non-calcareous; so he writes
_Protoderma_ (first cover) and places the species number 1 on the long
list of endosporous forms. Even in his '_Dodatek_', or supplement, as we
should say, he refers to the thing again, but only to correct the
inflexional ending of the specific name; he writes _Protoderma pusillum_
(Schrader) Rost!

Schweinitz reports the species for America and Morgan cites Schweinitz
and reports it for Ohio, but we find it in no American collections.

_B._ ORCADELLACEAE;

Sporangia distinct, minute, long stipitate, opening above by a distinct
lid.

A single genus,--

=Orcadella= _Wingate_

1889. _Orcadella_ Wingate, _Proc. Phil. Acad._, p. 280.

S