LIZARD 733 conical, pointed, more rarely blunt, or notched at the top or sides. Always anchylosed with the bone, they are inserted either on the inner side of the margin of the jaws (pleurodontef), or on the edge of the bones (acrodontes). The form of the tongue exhibits many modifications which have been used for the division of the order into families, as will be seen from the systematic list given below. All lizards are oviparous, the eggs being of an oval shape, and covered with a hard or leathery calcareous shell. The number of eggs laid is, in comparison with other reptiles small, perhaps never exceeding forty, and some, like the anolis and geckos, deposit only one or two at a time, but probably the act of oviposition is repeated in these lizards at frequent intervals. The parents do not take care of their progeny, and leave the eggs to hatch where they were deposited. In a few lizards, however, the eggs are retained in the oviduct until the embryo is fully developed ; these species, then, bring forth living young, and are called ovoviviparous. No lizard is venomous, with, perhaps, a single exception (Heloderma) to be mentioned hereafter. The order of lizards may be divided into the following suborders and families : First Suborder. Cionocrania. Vertebra proccclian ; an orbital ring with a temporal bar more or less complete ; columella present ; parietal bone single. Family 1. Monitoridse. Scales of the belly oblong, quadrangular, in cross-bands, on the back and tail rhombic, very small or granular. Tongue very long, exsertile, ending in two long filaments, sheathed at the base. Head with small polygonal shields. The largest lizards, inhabiting the African, Indian, and Australian regions. Genera: Psammosaiirus, Odatria, Yaranus (Monitor), Hydrosaurus. Family 2. Tcjidss. Scales small, granular, sometimes with larger tubercles ; those of the belly oblong, quadrangular, in cross .bands. Head with large symmetrical scutes. Tongue long, scaly, bifid at the end. Dentition acrodont. No fold of the skin along the sides. Tropical and subtropical America. Genera : Tejus, C allopistes, Ameiva, Cnemidophorus, Dicrodon, Acrantus, Centropyx, Crocodilurus, Ada, Custa. Family 3. Lacertidse. Scutellation as in the preceding family. Tongue long, exsertile, bifid at the end, without sheath at the base. Dentition pleurodont. Old World, especially from the Europo- Asiatic, African, and Indian regions. Genera : Lacerta, Tropidosaura, TachydroTWU, Ichnotropis. Acanthodactylu?, Psammodromus, Scrapteira, Eremias, Mesalina, Cabrita, Ophiops, Chondrophiops, Tracheloptijchus. Family 4. Xanthusiidas. Distinguished from the preceding family by a broader nou-exsertile tongue. California, Central America, and Cuba. Genera: Xanthusia, Lepidophyma, CHcosaura. Family 5. Trachydermi. Scales arranged in transverse rows, frequently swollen or tubercular. Tongue ending in two short points. Dentition pleurodont. Xo femoral pores. v Central America, extending into the subtropical parts of North America. Genera : ffeloderma, Gerrhonotus. Family 6. Zonuridss. Scales arranged in transverse rows, quad rangular, those of the back generally keeled ; a fold of the skin runs along the side of the body, separating the upper from the lower parts. Head with large symmetrical shields. Tympanum distinct. African region ; Pseudopus from the Europe-Asiatic, and Ophisaurns from the North American region. Genera: Cordylm, Zonurvs, Ptotysaurus, Gerr/iosaurus, Pleurostrichus Saur- 02~>nis, Caitia, Pseudopus, Optiisaurus, Hyalosaurus. Family 7. Ckakididso. Scales arranged in transverse bands, quadrangular ; scarcely a trace of a lateral fold in front. Head with large symmetrical shields. Tongue scaly, bifid in front. Typanum hidden. Body long, with rudimentary limbs. Tropical America. Genera : Brac/iypus, Uicrodactylus, Chalcis, Ophiognomon, Sachia, Propus ffeterodactylus. Family 8. Cercosauridse. Scales rhombic or quadrangular, gene rally arranged in transverse series. No lateral fold, or only a trace of it. Head with large symmetrical shields. Tongue scaly, bifid in front. Tympanum distinct. Body moderately elongate, with four developed limbs. Males with femoral pores. Tropical America. Genera : Cercosaura, Pantodactylus, Chalcidolepi.t. Iphisa, Perodactylus, Placo- tonia, Holaspis. Lepidosoma, Ecpleopus, Euspondulut, Cricosaiira, Procloporus, l/rosaura, Emphrassotis, Lepidophyma, LoxophoUs, Tretioscincus. Family 9. CfiamsMaurid&.Bodj slender, with rudimentary limbs. Scales arranged in transverse series, equal all round the body, provided with a sharp keel, the keels forming longitudinal ridges ; no lateral fold. Typanum distinct. Tongue with a very shallow notch in front. South Africa. Genus : Chamxsaura. Family 10. Gymnophthalmid&. The entire body is covered with rounded imbricate quincuncial scales; head with symmetrical shields. No eyelids. Nostrils lateral, in a single shield. Body long, with the limbs small or rudimentary. Irregularly distributed over the tropical regions. Genera: Gymnop?it?ialmus, Epapheltts, Ablepharus, Blepharosteret, Cryptoble- pharus, Morethia, Menetia, Miculia, Lerista, Elepharactisis. Family 11. Pygopodidx. Scutellation as in the preceding family, ! but the nostrils are situated above the upper edge of the first labial I shield. No eyelids. Body long, with a pair of rudimentary hind limbs only. Australia. Genera : Pygopus, Delma, Family 12. Aprasiidx. Scutellation as in the preceding families, the nostrils in a suture between the nasal and first labial shields. No eyelids. Limbs none. Australia. Genus : Aprasia. Family 13. Lialidx. Scales imbricate, quincuncially arranged ; head with} imbricate scale-like shields. No eyelids. Body long, with a pair of rudimentary hind limbs only. Australia. Genus : Lialis. Family 14. Scincidse. The entire body is covered with rounded imbricate scales, quincuncially arranged ; head with symmetrical shields. Eyelids developed. Nostrils behind the rostral, in a separate shield, or between two or three small shields. Tongue
- short, with a notch in front. Ground-lizards. This family has so
i wide a distribution that its range almost coincides with that of the j order generally. The following genera are composed of numerous species, and extend over several geographical regions : Hinulia (Indian and Australian regions), umeces, including Mocoa and Riopa, Lyyosoma and Chelomeles (Indian and Australian regions), Plestiodon (Europo-Asiatic, North American, and Indian regions),
- Mabouia and Tiliqua (Euprepes), generally distributed in the tropical and sub-
I tropical regions, lleteropus (Indian and Australian regions), Sphenops and Gon- gylus (Europo-Asiatic and African regions). Indian genera: Lipinia, Antphixeftus, Lygosuiirus, Cophoscineus, Ristella. Podop/iif, C/iiamela, Senira, Brachymeles, Hayi-ia, Tropidophorus, Xorbea, Dasia. Sphenocephalus, Sepophis. Australian genera: Hemiergis, Tetradactylus, Omolepida, Siaphos, Anoma- lopits, Rhodona, Ophioscincus, Soridia, Lioscincus, Tribolonotus, Tracliydosaurus, Corucia, Cyclodui, Silubosaums, E jernia, Tropidolepisma, Tropidoscincui, Nan- noscincus, Ophioseps. Tropical American genera : Opliiodes, Celestus, Camilia, Diploglossus, Sauresia, I Panolopus. African genera : Liolepisma, Dumerilia, Pygomeles, Eumecia, Sedates, Thyrus, Amphiglossus, Sepsina, Sepomorphtts, Herpetosaura, Sepacontias. Europo-Asiatic genera: Scincus, Anguis, Ophiomorus, Zygnopsis, Hemipodion, Seps, Heteromeles. North American genus : Anniella. Family 15. Acontiidas. Scutellation similar to that of the skinks, but the rostral shield is enlarged, cup-shaped, the nostril being in the rostral, with a long slit between it and the hinder margin of the rostral. Eyes distinct, with a lower eyelid. Limbs rudi mentary or absent. Africa, Madagascar, and Ceylon. Genera : Nessia, Eresia, Acontias, Aparallactus. Family 16. Typlilinidas. Differing from the preceding family by having the eyes hidden under the skin. Africa, East Indian Archi pelago, New Guinea. Genera : TypMosaitrus, Feylinia, Dibatmts. Family 17. Iguanidss. Scales of the back and sides imbricate, generally in transverse, oblique rows, those of the belly similar ; head with numerous, irregular small scutes. Tongue short, scarcely notched in front, not exsertile. Dentition pleurodont ; teeth fre quently compressed towards the point. Toes 5-5. The whole of this large family are found in the New World, with the exception of two genera, one (Bracliylophus} inhabiting the Fiji Islands, the other (Hoplurus) Madagascar. The genera may be divided into two groups, one comprising arboreal forms with compressed slender body, slender legs, and long tail, the other forms, which live on the grounri, with a broader, more depressed body, stouter legs, and shorter tail. Both groups pass into each other. Arboreal genera : Po/ychrus, Urotrophus, Ecpfiymotes. Ltemanedts, Iguana, Ahponotus, Krachylophus, Aletopoceros. Trachycephalus, Oreocephalus, Cyclura, Cttnosaura, Enyatiosaurus, Basiliscns, Corythasolus, Corythophanes, Chamie- leopsis, Ophryoessa, Ophruoessoides, Enyalius, Chamxleolis, Xiphosurttf, Dactyloa. Xiphocercus, Acantholis. Xorops, Anolis, Vraniscodon, Plica. Terrestrial genera : Tropidolepis (Sceloponis), Liodera, Liolxmus. Pi/yoderus, Procto/retus, Lioeephaltts, Hetocephaltis, Scartiscns, Stenocercus, Trachycyclus. Holbrookia, Uta, Anevporus, Tarctftuira, Tropidtiiits, Microphrattus, Aniso- pfiraftitf, Hop/urns, Jloplocercus, Strobilurus, Liosaurus. Diplolxmus, Sauro- malus. Cacftryj-, Cranocentron. Crotaphyttis, Phymalurus, Centrum, Callisaurus, L ma, Tropidogaster, Phrynosoma. Family IS. Arjamidse. Differing from the preceding family by their acrodont dentition. Tropical regions of the Old World and Central Asia. Arboreal Indian genera: Draco, Sitana. Lynocephaltis, Arpfphonts, Cerato- phora, Cophotis, Otocryptis, Gonyocephalits, Japalura, Dilophyrus, Orotiaris, Tiarif, Acanthosaura. Calotft. lii-nnchoccela, Salea, Lophocalotes, ffypselurus, Gonyocephalus, Lophura, Physignathus.
