a genus of squamate reptiles of the family Amphisbaenidae. Lizards of this genus have a marked cutaneous fold on both sides of the body. The eyes are covered by skin and show through as small dark spots. The animals measure as much as 25 cm in length. In contrast to all other members of the Amphisbaenidae, they have weakly developed anterior extremities with three or five digits, usually all the same size, with small claws.
The genus consists of three species: B. canaliculatus, B. tridactylus, and B. biporus. The lizards are distributed in the southern part of Baja California and in Western Mexico. They are burrowers and are also found in the nests of ants and termites. They feed on small invertebrates.