num·mu·lite 
(nŭmyə-līt′)
(nŭmyə-līt′)n.
A large, coin-shaped, fossil foraminifer of the genus Nummulites, widely distributed in limestone formations from the Eocene Epoch to the Miocene Epoch of the Cenozoic.
[From New Latin Nummulītēs, type genus, from Latin nummulus, diminutive of nummus, coin, probably from Greek nomimos, customary, legal; see nem- in the Appendix of Indo-European roots.]
num′mu·litic (-lĭtĭk) adj.