The outer membrane of the calyculus is by no means always absent.
It differs from all other American forms, so far described, in the peculiar development of the calyculus.
The colors are obscure, but the striations on the calyculus are violet-tinted, and the reds perhaps predominate elsewhere.
This common species is well marked both by its color and by the delicate attachment of the capillitium to the calyculus.
Sporangium ovoid, more or less elongated; the calyculus small, plicate-sulcate.
Sporangium ovoid-oblong; the calyculus small, sulcate and ribbed, granulose.
Sporangium ovoid; the calyculus very small, finely ribbed and granulose.
Sporangium cylindric; the calyculus small, granulose, ribbed and sulcate.
Sporangium oblong-ovoid, stipitate; the calyculus small, thin, smooth.
The calyculus is variable in size; in some examples the thin connecting membrane between the ribs has disappeared.
