Wallace's line

noun

Wal·​lace's line ˈwä-lə-səz- 

: a hypothetical boundary that separates the highly distinctive faunas of the Asian and Australian biogeographic regions and passes between the islands of Bali and Lombok in Indonesia, between Borneo and Sulawesi, and between the Philippines and the Moluccas

Word History

Etymology

Alfred Russel Wallace

First Known Use

circa 1868, in the meaning defined above