What is an extinct genus of cyathophylloid corals common in the Paleozoic formations. It is cup-shaped with numerous septa, and with a deep pit in one side of the cup called?

zaphrentis — An extinct genus of cyathophylloid corals common in the Paleozoic formations. It is cup-shaped with numerous septa, and with a deep pit in one side of the cup. (Webster's 1913.)

Sources