They retire into self-dug burrows. _Cophias_ and _Scolecosaurus_ have very much reduced limbs. In the genus _Tejus_ the teeth of the adult become molar-like; and in _Dracaena_ they are transformed into large, oval crushers, indicating strictly herbivorous habits, while most members of the family live upon animal food. Family 10. _Amphisbaenidae._--The body is covered with soft skin, forming numerous rings with mere vestiges of scales. Worm-shaped, without limbs, except _Chirotes_ which has short, clawed fore-limbs. Eyes and ears concealed. Tongue slightly elongated, covered with scale-like papillae and bifurcating. Tail extremely short. Acrodont or pleurodont. America, Mediterranean countries, and Africa with the exception of Madagascar. _Chirotes canaliculatus_, and two other species; Pacific side of Mexico and Lower California. With five, four or three claws on the stout little digging fore-limbs. These pink, worm-like creatures live in sandy, moist localities, burrowing little tunnels and never appearing on the surface. _Amphisbaena_ (q.v.). _Rhinëura_ of Florida, and also known from the Oligocene of South Dakota; _Lepidosternum_ of South America; and _Anops_ in America and Africa; _Blanus cinereus_, Mediterranean countries. _Trogonophis_, _Pachycalamus_ and _Agamodon_ of Africa are all acrodont; the other genera are pleurodont. In all about a dozen genera, with some 60, mostly tropical species. Family 11. _Scincidae._--Pleurodont. Tongue scaly, feebly nicked in front. Osteoderms on the head and body. Limbs often reduced. Cosmopolitan. The temporal region is covered over, as in the _Lacertidae_ and _Anguidae_, with strongly developed dermal ossifications. Similar osteoderms underlie the scales of the body and tail. Femoral pores are absent. All the skinks seem to be viviparous, and they prefer dry, sandy ground, in which they burrow and move quickly about in search of their animal food. This partly subterranean life is correlated with the frequent reduction of the limbs which, in closely allied forms, show every stage from fully developed, five-clawed limbs to complete absence. Some have functional fore-limbs but mere vestiges of hind-limbs; in others this condition is reversed. In some deserticolous kinds e.g. _Ablepharus_, the lower eyelid is transformed into a transparent cover which is fused with the rim of the reduced upper lid. The same applies to the limbless little _Ophiopsiseps nasutus_ of Australia. This large family contains about 400 species, with numerous genera; the greatest diversity in numbers and forms occurs in the tropical parts of the Old World, especially in the Australian region, inclusive of many of the Pacific islands. New Zealand has at least 6 species of _Lygosoma_. America, notably South America, has comparatively very few skinks.