Lacertilia.
Having a single transverse process on each side, single-headed ribs, two external nostrils, eyes with movable lids; body covered with horny, sometimes bony, scales.
Lacerta—the Monitors, Crocodiles, Lizards; having ambulatory limbs.
Anguis—Ophisaurus, Bimanus, Chalcides, Seps; limbs abortive; no sacrum.