Boinae

Boinae, a subfamily of Boidae, are the true boas. Genera include Boa (boa constrictors), Candoia (ground boas), Corallus (tree boas), Epicrates (rainbow boas), Eunectes (anacondas), Sanzinia (Madagascan tree boa), Trachyboa (eyelash boas) and Xenoboa (Cropan’s boa). When heat-sensitive pits are present they are situated between the labial scales, unlike those of pythons that are within the scales. All are believed to be viviparous.