saccocoma

from The Century Dictionary.

• noun A genus of articulate crinoids constituting the only known genus of the Saccocomidæ. They are stemless, the calyx being composed of radial plates with an extremely small single basal, the arm-plates carrying wing-like expansions on each side of the ambulacral furrows, and the entire skeleton having a reticulated surface. They occur in the Jurassic limestone of Solnhofen, Bavaria.