merostomata Meaning, Definition & Usage

  1. noun used in some classifications; includes the orders Xiphosura and Eurypterida
    class Merostomata.

WordNet

Mer`o*stom"a*ta noun plural
Etymology
NL., fr. Gr. thigh + , -, mouth.
Definitions
  1. (Zoöl.) A class of Arthropoda, allied to the Crustacea. It includes the trilobites, Eurypteroidea, and Limuloidea. All are extinct except the horseshoe crabs of the last group. See Limulus.

Webster 1913