What is an order of brachiopods, in which the valves of shell are not articulated by a hinge. It includes the Lingula, Discina, and allied forms. [Written also Lyopoma.] called?

lyopomata — An order of brachiopods, in which the valves of shell are not articulated by a hinge. It includes the Lingula, Discina, and allied forms. [Written also Lyopoma.]. (Webster's 1913.)

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