SPORANGIA: sessile, subglobose or obovoid, 0.4 to 0.6 mm. diam., or reniform and elongate on a broad base, free or more often crowded in colonies, often angled by mutual pressure, rounded above or flattened, smooth and yellow, ochraceous, or white.

PERIDIUM: double, the outer layer thick with dense deposits of lime, often breaking away in the upper part from the thin, colorless, inner layer.

CAPILLITIUM: with scanty hyaline threads and numerous large, irregularly branching, white or yellowish lime-knots, occasionally densely massed in the middle.

NOTES: This species is variable in the manner of sporangial formation. Usually, the sporangia are densely compacted in small clusters, but may be perfectly free and sometimes with vestiges of short stalks. The walls may be uniformly dense with lime, and the tops confluent, appearing as a pseudo-aethalium, or, the lower parts only may be stout, persisting as distinct cups.