Other genera are _Psammodromus_ and _Acanthodactylus_ in south-western Europe and northern Africa. _Cabrita_ in India, with transparent lower eyelids. _Ophiops_, likewise with transparent but united lids, from North Africa to India. Family 16. _Varanidae._--Pleurodont. Tongue very long, smooth and bifid. Osteoderms absent. Limbs always well developed. Old World. This family contains only one genus, _Varanus_, with nearly 30 species, in Africa, Arabia and southern Asia, and Australia, but not in Madagascar. The generic term is derived from the Arabic _Ouaran_, which means lizard. Owing to a ridiculous muddle, this Arabic word has been taken to mean "warning" lizard, hence the Latin _Monitor_, one of the many synonyms of this genus, now often used as the vernacular. Many of the "monitors" are semi-aquatic, e.g. _V. niloticus_, and these have a laterally compressed tail; others inhabit dry sandy districts, e.g. _V. scincus_, the _ouaran el ard_ of North Africa; others prefer wooded localities. _V. salvator_ is the largest species, reaching a length of 7 ft.; it ranges from Nepal and southern China to Cape York; a smaller species, common in New Guinea and Australia, is _V. gouldi_. They all are predaceous, powerful creatures, with a partiality for eggs. Their own eggs are laid in hollow trees, or buried in the sand. The young are prettily spotted with white and black ocelli, but the coloration of the adult is mostly very plain. [Illustration: FIG. 3.--Monitor of the Nile (_Varanus niloticus_).] The following families are much degraded in conformity with their, in most cases, subterranean life. They are of doubtful relationships and contain each but a few species. Family 17. _Pygopodidae._--Pleurodont, snake-shaped, covered with roundish, imbricating scales. Tail long and brittle. Fore-limbs absent; hind-limbs transformed into a pair of scale-covered flaps. Tongue slightly forked. Eyes functional but devoid of movable lids. Australia, Tasmania and New Guinea. _Pygopus_, e.g. _P. lepidopus_, about 2 ft. long, two-thirds belonging to the tail, distributed over the whole of Australia. _Lialis burtoni_, of similar size and distribution, has the hind-limbs reduced to very small, narrow appendages. The members of this family seem to lead a snake-like life, not subterranean, and some are said to eat other lizards. _L. jicari_, from the Fly river, has a very snake-like appearance, with a long, pointed snout like certain tree-snakes, but with an easily visible ear-opening; their eyelids are reduced to a ring which is composed of two or three rows of small scales. (H. F. G.) FOOTNOTE: [1] For the etymology of this word, see CROCODILE. [2] For anatomical detail and experiments, see R. W. Shufeldt, _P. Z. S._ (1890), p. 178; G. A. Boulenger, _ibid._ (1891), p. 109, and C. Stewart, _ibid._ (1891), p. 119.