inkled, filled with irregular yellow masses of lime
and accordingly bright yellow in color; columella none; capillitium
forming a dense net, with comparatively small yellow nodular
thickenings; spores globose, purplish, each minutely papillose and
displaying several scattered spots occasioned by local development of
the papillae; diameter of the spores 9-10 mu.

This species was set up for the reception of certain material collected
by Professor Shimek, in 1892, in Nicaragua. It remains so far unique.
The small globose sporangium mounted upon a long upwardly tapering
stipe, .5 mm. thick below, but narrowed at the extreme base where it is
lightly attached, a stem which is simply a sack stuffed with yellow
lime-granules;--this and the yellow capillitium are distinguishing
features. The capillitium and spores suggest _Tilmadoche viride_, but
the entire habit precludes such reference. Perhaps nearest to _P.
melleum_.

Castillo, Nicaragua.

Miss Lister thinks this the same as _P. tenerum_ Rex. But the whole
habit and external appearance are different; the stipe notably long,
clumsy, surcharged with lime; a very singular form.

36. PHYSARUM DIDERMOIDES (_Pers._) _Rost._

PLATE IX., Figs. 1, 1 _a_, 1 _b_, 1 _c_.

1801. _Spumaria (?) didermoides_ Acharius, Pers., _Syn. Fung._,
p. xxix.
1829. _Diderma oblongum_ Fr., _Syst. Myc._, III., p. 103.
1831. _Spumaria licheniformis_ Schw., _N. A. F._, p. 261, No. 2364.
1832. _Physarum atrum_ Schw., _Syn. Fung., Am. Bor._, p. 258.
1875. _Physarum lividum_, Schw., Rostafinski, _Mon._, p. 96.
1875. _Physarum didermoides_ (Ach.) Rost., _Mon._, p. 97.

Plasmodium pale, watery-white or gray; sporangia crowded, ovoid or
cylindric, stipitate or sessile, blue-gray, often capped with white;
stipe variable in length and structure, where well developed pure white,
often flattened, expanded and diaphanous, connate with others through
the irregular reticulate or sheet-like hypothallus; columella none;
capillitium ample, the lime knots angular or rounded, white connected by
hyaline threads; spores in mass black, by transmitted light dark violet,
decidedly spinulose, 12-15 mu.

A very variable species in many particulars. The sporangia in the same
cluster are stipitate and sessile, ovoid and spherical. Our description
does not quite agree with that of Rostafinski. As may be seen from the
plate, it is the _outer_ peridium that is with us white, burdened with
lime, th