The maxillaries are typically horizontal, not separately movable, with a series of teeth.
The maxillaries are connected with the distal anterior corner of the quadrate by the thin, splint-like jugal and quadratojugal.
Snakes possess teeth in the maxillaries, mandibles, palatine and pterygoid bones, sometimes also in the intermaxillary; they may be absent in one or the ether of the bones mentioned.
In some all the teeth are nearly of the same size; others possess in front of the jaws (Lycodonts) or behind in the maxillaries (Diacrasterians) a tooth more or less con spicuously larger than the rest; whilst others again are distinguished by this larger posterior tooth being grooved along its outer face.
Eyes free; with a pair of poison-fangs in the front part of the mouth, carried by the otherwise toothless, much shortened, and vertically erectile maxillaries; ventral scales transversely enlarged: Viperidae.