Source : Webster's Revised Unabridged Dictionary (1913)

Perissodactyla \Per`is*so*dac"ty*la\, n. pl. [NL., from Gr. ?
   odd (fr. ? over) + ? finger.] (Zo["o]l.)
   A division of ungulate mammals, including those that have an
   odd number of toes, as the horse, tapir, and rhinoceros; --
   opposed to Artiodactyla.

Source : WordNet®

Perissodactyla
     n : nonruminant ungulates: horses; tapirs; rhinoceros; extinct
         forms [syn: {order Perissodactyla}]