ivaceous.

This order is readily recognized by the spiral ridges which wind around
the tubules of the capillitium.

TABLE OF GENERA OF TRICHIACEAE.

1. HEMIARCYRIA. Capillitium of long slender tubules, arising from the
base of the sporangium, or issuing from the interior of the stipe; the
spiral ridges parallel and conspicuous.

2. CALONEMA. Capillitium of slender tubules, arising from the base of
the sporangium; the surface traversed by a system of branching veins.

3. TRICHIA. Capillitium consisting of numerous short slender tubules,
called elaters, which are wholly free; the spiral ridges parallel and
conspicuous.

4. OLIGONEMA. Capillitium scanty, composed of elaters habitually
irregular and abnormal; the surface variously marked.

I. HEMIARCYRIA, Fr. Sporangia regular and stipitate, rarely
plasmodiocarp, the wall at maturity breaking away from above downward,
leaving more or less of the lower portion persistent. Stipe more or less
elongated, rarely wanting, resting on a thin hypothallus. Capillitium of
long slender tubules, more or less branched, arising from the base of
the sporangium, or issuing from the interior of the stipe; the spiral
ridges parallel and conspicuous, 3-5, rarely more in number, smooth or
spinulose. Spores globose, red, yellow.

The genus is related on the one hand to Arcyria by the mode of
attachment of the threads, on the other hand to Trichia, by the parallel
spiral ridges which wind around them. By the mode of branching of the
threads, the species fall readily into two sections.

Sec.1. ARCYRIOIDES. Capillitium of slender threads, branching and
anastomosing, thus forming a more or less evident network.

In some of the species the large irregular meshes of the network are
scarcely to be discerned, but are rather to be inferred from the
abundant branching of the threads and the paucity of the free
extremities.

1. HEMIARCYRIA PLUMOSA, Morgan, n. sp. Sporangium obovoid to turbinate,
olive-yellow to olive-brown in color, stipitate; the wall densely
granulose within, externally smooth and shining, the upper part soon
disappearing, leaving a funnel-shaped persistent base. Stipe long,
erect, reddish-brown, arising from a thin hypothallus. Capillitium of
threads 5-7 mic. in thickness, repeatedly branched and anastomosing, to
form a dense network without any free extremities, olive-yellow to
olive-brown in color; the spiral ridges five or six, close, smooth.
Spores in mass, lemon-yel