Collier's New Encyclopedia

A complete general encyclopedia of 1921 — the world as it was understood just after the Great War, from Aachen to Zwingli, across twelve volumes and six thousand pages.

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Rugosa

in zoölogy, a group of Madreporaria; corallum sclerodermic with a true theca; generally both tubulæ and septa combined; septa generally some multiple of four, but with one or three prominent, or with a small channel; simple or con pound corals represented in the modern seas only by two genera, one from the Mediterranean, the other from Florida. Families: Stauridx, Cyathaxonidæ, Cyathophyllidæ, and Cystiphyllidæ. Also found in the Palæozoic rocks, the Upper Greensand, and the Tertiary.

They were reef-builders.

RUHR (rör), a river of Prussia, that joins the Rhine at Ruhrort, about 15 miles N. of Düsseldorf. It rises in Westphalia, and has a tortuous course of about 200 miles, latterly through the Ruhr coal field region.

Germany,

← RugerRuhr District →