s are
completely merged in one; in others traces of coalescence remain. The
number of united sporangia varies. There are some clusters before us
containing 16 and 18 in a single fascicle!

Not very common. On rotten wood of deciduous trees, especially south.

New England, Pennsylvania, Ohio; Black Hills, South Dakota, and south to
Nicaragua.

_Arcyria bicolor_ Berk. & C. seems to refer to the fact that the
sporangia have sometimes an ochraceous tint. Berkeley's specimens are
from Cuba. Our latest specimens are from Nicaragua; the form seems not
to be reported from the old world.

11. ARCYRIA POMIFORMIS (_Leers_) _Rost._

1775. _Mucor pomiformis_ Leers, _Flor. Herb._, p. 218.
1875. _Arcyria pomiformis_ Rost., _Mon._, p. 271.

Sporangia scattered, gregarious, globose, bright yellow, very minute,
.5 mm. high, .3 mm. in diameter, stipitate; stipe short, one-third the
total height, pale brown or yellow; hypothallus none; capillitium loose,
freely expanding, not deciduous, honey-yellow, the threads generally
wide, 4-5 mu, toward the periphery more narrow, 2.5 mu warted, marked with
blunt spinules, which not infrequently pass into distinct transverse,
narrow plates or half-rings, free ends clavate and numerous; spore-mass
yellow, spores by transmitted light smooth, granular, globose, 7-9 mu.

This species as represented by the material before us seems constant in
size, color, and microscopic characters, in all which it differs from
all species here listed. It resembles somewhat _Lachnobolus globosus_
Schw., but differs in habit, habitat, color, the capillitium, its
attachment and in the mode of dehiscence. In the present species the
wall is evanescent almost _in toto_; in _L. globosus_ is it remarkably
persistent, and the capillitium is adherent.

Probably rare. Its smallness removes it from sight of all but the most
exact collectors. Maine, New York, South Carolina, Alabama, Missouri,
Iowa; Black Hills, South Dakota; Ontario;--_Miss Currie._

While usually remotely gregarious a collection from southern California
shows that on occasion the entire plasmodium may pass to fruit with
narrowest limits, forming a stipitate, compact, globose mass of crowded,
superimposed sporangia as in _Oligonema nitens_. Set Plate XX., Fig. 12.

12. ARCYRIA INSIGNIS _Kalkbr. & Cke._

1882. _Arcyria insignis_ Kalkbr. & Cke., _Grev._, X., p. 143.
1911. _Arcyria insignis_ Kalkbr. & Cke., List., _Mycet., 2nd ed._,