The Collaborative International Dictionary of English v.0.48:

Numismatologist \Nu*mis`ma*tol"o*gist\, n.
   One versed in numismatology; usually called a numismatist.
   [1913 Webster]

WordNet (r) 3.0 (2006):

numismatologist
    n 1: a collector and student of money (and coins in particular)
         [syn: numismatist, numismatologist, coin collector]