What does "ginglymodi" mean?

Ginglymodi: An order of ganoid fishes, including the modern gar pikes and many allied fossil forms. They have rhombic, ganoid scales, a heterocercal tail, paired fins without an axis, fulcra on the fins, and a bony skeleton, with the vertebræ convex in front and concave behind, forming a ball and socket joint. See Ganoidel.