Note: Genus name introduced by the Austrian zoologist Leopold Fitzinger (1802-84) in Neue Classification der Reptilien nach ihren natürlichen Verwandtschaften, Vienna, 1826, pp. 31, 60. Fitzinger gives no clue to the origin of the name, a redesignation of Coluber irregularis, defined by Blasius Merrem. A derivation from the genus name Boa is implausible, both because this snake is not closely related to the Boidae and because -iga is not a recognizable suffix.