The Collaborative International Dictionary of English v.0.48:

Arion \Arion\, prop. n.
   In Greek legend, a fabulous horse, the offspring of Poseidon
   by Demeter (or, in other accounts, Gaea or a harpy) who to
   escape him had metamorphosed herself into a mare. It was
   successively owned by Copreus, Oncus, Heracles, and Adrastus.
   It possessed marvelous powers of speech, and its right feet
   were those of a man.
   [Century Dict. 1906]

U.S. Gazetteer Places (2000):

Arion, IA -- U.S. city in Iowa
   Population (2000):    136
   Housing Units (2000): 61
   Land area (2000):     0.474903 sq. miles (1.229992 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.474903 sq. miles (1.229992 sq. km)
   FIPS code:            02755
   Located within:       Iowa (IA), FIPS 19
   Location:             41.949194 N, 95.462955 W
   ZIP Codes (1990):     51520
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Arion, IA
    Arion