Typhlopidae:

Similar to the related families Anomalepidae and Leptotypholidae, the typhlopids are small snakes (usually <30 cm, Typhlops schlegeli up to 1 m) with blunt heads and short, blunt tails. Due to their burrowing life style their eyes are vestigial. In addition, they lack enlarged ventral scales as other snakes. Typhlopids share toothed, movable maxilla with anomalepids but differ in having pelvic vestiges and in not having the prefrontal bones extend poteriorly over the orbits. In typhlopids the premaxilla is toothless and firmly articulated with the snout.The maxillae bear several teeth and are attached to the skull via mobile articulations. The lower jaw is composed of an enormous compund bone, a large separate coronoid, a small splenial and angular, and a small toothless dentary. Members of the genus Ramphotyphlops are unusual among squamates in having a solid protrusible hemipenis rather than an eversible hollow structure.