peridium

"Whether the thread is hollow or solid, simple or branched, free or connected with the peridium or a columella,—these are entirely secondary conditions, depending on the extent and form of the vacuoles."

From The North American Slime-Moulds A Descriptive List of All Species of Myxomycetes Hitherto Reported from the Continent of North America, with Notes on Some Extra-Limital Species by Thomas H. (Thomas Huston) MacBride

This species resembles B. capsulifera, but is distinguished by a more strongly rugulose less calcareous peridium and a more profuse development of filamentous stipes, but especially by the character of the spores.

From The North American Slime-Moulds A Descriptive List of All Species of Myxomycetes Hitherto Reported from the Continent of North America, with Notes on Some Extra-Limital Species by Thomas H. (Thomas Huston) MacBride

B, Part of vertical section through leaf of Berberis vulgaris, with a, aecidium fruits, p, peridium, and sp, spermogonia.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 "Frost" to "Fyzabad" by Various

The author hesitated about the generic reference, finally referring it to Diachaea despite the lack of calcium, because it was sessile and had a peridium rather more persistent than is usual in comatrichas.

From The North American Slime-Moulds A Descriptive List of All Species of Myxomycetes Hitherto Reported from the Continent of North America, with Notes on Some Extra-Limital Species by Thomas H. (Thomas Huston) MacBride

The persistent warts which cover the surface of the peridium are so minute as to appear to the naked eye like scales.

From Student's Hand-book of Mushrooms of America, Edible and Poisonous by Thomas Taylor