cup corals

from The Collaborative International Dictionary of English v.0.48
Cyathophylloid \Cy`a*tho*phyl"loid\, n. (Paleon.)
   A fossil coral of the family {Cyathophyllid[ae]}; sometimes
   extended to fossil corals of other related families belonging
   to the group Rugosa; -- also called {cup corals}. Thay are
   found in paleozoic rocks.
   [1913 Webster]
    

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