m gray or drab-colored, very slightly
attached to the bottom of the calyculus, far expanded, forming a
loose-meshed net, the threads regular, cylindric, coarsely sculptured
with rings, half-rings, cogs, spines, etc.; spores in mass dull gray,
drab, under the lens colorless, papillate, with few papillae, 7-8 mu.

This magnificent form resembles in habit and general appearance, save
color, _A. nutans_. The capillitium is, however, very different both in
the sculpture and in the more delicate markings of the threads. Dr. Rex,
_l. c._, has pointed out the lack of reticulation on the capillitium and
calyculus. The color is also diagnostic. A roseate variety seems to
occur with the present form. This is _A. magna rosea_ Rex, and appears
to agree with the type in all respects save color. The relationship here
must be determined by future inquiry. The capillitial threads are
remarkable for their graceful slenderness, regularity, and symmetry.

2. ARCYRIA OERSTEDTII _Rost._

1875. _Arcyria oerstedtii_ Rost., _Mon._, p. 278, Fig. 196.

Sporangia cylindric, arcuate, 1.5 mm. high when unexpanded, closely
clustered, dull crimson, stipitate; peridium evanescent except here and
there a persistent patch, the calyculus shallow, plicate, papillose
within; stipe short, weak, concolorous; hypothallus distinct,
membranous, concolorous; capillitium a loose, far-expanding, elastic
net, the meshes uneven, often small, the threads characterized by much
irregularity and many bulbose thickenings, especially at the nodes,
strongly spinulose throughout; spore-mass crimson or reddish brown,
dull; spores by transmitted light colorless, nearly smooth, sub-globose,
9-10 mu.

This well-marked species is certainly rare within our limits. We have
specimens from New England and from Pennsylvania. The Iowa material
referred to this species, _Bull. Lab. Nat. Hist. Ia._, II., p. 125, is
_A. magna_ Rex. Rostafinski's figure is excellent in the present case,
and gives the idea of what we regard the typical marking of the
capillitium in _A. oerstedtii_. Externally the species resembles
somewhat _A. nodulosa_, and the network of the capillitium is also
suggestive of that form; the spiny capillitium is unique.

Rare. Adirondacks, New York--_Dr. Rex._

3. ARCYRIA NUTANS (_Bull._) _Grev._

PLATE II., Figs. 6, 6 _a_, 6 _b_.

1791. _Trichia nutans_ Bulliard, _Champ._, p. 122, t. 502, III.
1794. _Arcyria flava_ Pers., _Roemer N. Mag. Bot._, I., p.