Meaning of Wallace's line

Wal'lace's line'

Pronunciation: [key]
— Zoogeog. Zoogeog.
  1. an imaginary line that separates the Oriental and Australian zoogeographical regions and passes between Bali and Lombok, west of Celebes, and east of the Philippines.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.