A hollow seen on the radial aspect of the wrist when the thumb is extended fully; it is bounded by the prominences of the tendon of the extensor pollicis longus posteriorly and of the tendons of the extensor pollicis brevis and abductor pollicis longus anteriorly. The radial artery crosses the floor that is formed by the scaphoid and the trapezium bones. SYN: tabatière anatomique.