porangia furnished with rigid, unpolished stipes, blending above with
the substance of the thick unpolished walls; the operculum thin,
delicate, membranaceous.

A single species,--

1. ORCADELLA OPERCULATA _Wingate._

PLATE XII., Fig. 11.

1889. _Orcadella operculata_ Wingate, _Proc. Phil. Acad._, p. 280.

Sporangia scattered, gregarious, ellipsoidal, ovoid, obconical or nearly
globose, dull brown or blackish, the wall simple, thick, coarse, at the
top replaced by a delicate, thin, yellowish, iridescent, lustrous or
vernicose membrane which forms a circular, smooth, or wrinkled lid, soon
deciduous; stipe of varying height, rough from deposit of plasmodic
refuse; spores, in mass yellowish, globose, smooth, 8-11 mu.

This curious little species, well described by its discoverer, appears
to be very rare. At least it is seldom collected; overlooked by reason
of its minuteness. It is a stipitate licea, or a lid-covered cribraria;
perhaps nearer the former. It affects the bark of species of _Quercus_,
and seems to be associated there with _Clastoderma debaryanum. N. A.
F._, 2497.

Pennsylvania, Maine.

_C._ TUBIFERACEAE

Fructification aethalioid or of distinct sporangia; sporangia well
defined, tubular, often prismatic by mutual pressure, seated on a
common, well-marked hypothallus, at length dehiscent by the irregular
rupture of the peridium, in typical cases at the apex, its walls
remaining then otherwise entire; capillitial threads in No. 3, only.

=Key to the Genera of the Tubiferaceae=

_A._ Spores olivaceous; sporangia in one or several
series, 1. LINDBLADIA

_B._ Spores umber; sporangia in a single series 2. TUBIFERA

_C._ Sporangia stipitate; capillitium of tubular threads 3. ALWISIA

=1. Lindbladia= _Fries_

1849. _Lindbladia_ Fries, _Sum. Veg. Scand._, p. 449.

Fructification aethalioid; the sporangia short, tubular, sometimes
superimposed, sometimes forming a simple stratum, in the latter case
generally sessile, but sometimes short-stipitate, the peridium at first
entire, at length opening irregularly either at the sides or apex, beset
with granules; spores olivaceous.

This genus was established by Fries in 1849 to accommodate a single
species of wide distribution and somewhat varying habit, which is
neither a tubifera nor yet a cribraria and offers points of resemblance
to each. It is distinct in that the spo