IGUANA SPHENODON BREVILIXGUIA. 219 



Tympanic membrane usually exposed. Many of them have a spiny dorsal 

 crest, and change their colour like the Chamaeleons. 



The following Iguanas belong to the western hemisphere, and are pleurodont : 

 Polychrus marmoratus Guv., Brazil ; Iguana tuberculata ~La,u.r.=sapidissima 

 Merr., West Indies ; I. delicatisslma Laur., tropical America ; Cyclura carinata 

 Gray. Cuba ; Basiliscus mitratus Daud., South America. 



The following belong to the eastern hemisphere, and are acrodont : Calotes 

 ophiomachus Merr., East Indies ; Draco volans L., Java ; LopJiiura ambainensis 

 Schloss. 



The New Zealand genus, Hattcna = Sphenodon, which was formerly reckoned 

 among the Iguanidce, shows such considerable differences in its organization 

 that (runther established for it a third order of scaly Keptiles under the name 

 of Ehyncliocephalia, * which Huxley holds to be allied to the extinct Triassic 

 Lacertilian genera Ilijperodapedon and Rliyncliosaurus. 



Fam. Humivagae. Lizards with broad flat body, supported by shorter limbs ; 

 of almost toad-like aspect. The skin is not unfrequently covered with spiny 

 scales. They live on the ground in stony and sandy places, where they hide 

 themselves in pits and holes. 



To the Hiimivagce of America, which are all pleurodont, belong Phrynosoma 

 orliculare Wiegm., Tapayaxin, Mexico ; Tropidurus cyclurus Wied., Brazil. 



FIG. 641. Scincus offlcinalis (rdgne animal). 



To the Humivagce of East India and Africa, which are acrodont, and possess 

 canine teeth, belong Phrynoceplialus helioscopus Kp., Siberia ; Uromastix 

 spinipes Merr., Egypt ; Agama colon orum, Daud., Egypt ; Stellio vulgaris Latr., 

 Hardun, Egypt. 



Sub-order 4. Brevilinguia. Scaly Lizards, with elongated, often 

 snake-like body. The limbs are very diversely developed. The 

 tongue is short and thick, without sheath, more or less indented at 

 the thinner anterior end, and but slightly protrusible. Eyelids are, 

 as a rule, present. The tympanic membrane is often concealed 

 beneath the skin. , . 



Fam. Scincoideae. Sand-Lizards. The more or less snake-like body is covered 

 with smooth bony scales. The crown of the head is invested with larger scutes. 

 Anguis fragilis L., Blindworm, Europe ; Scincus qfficinalis Laur. (fig. 644) 

 Egypt ; Seps chalcidica Merr., Dalmatia; Acontias maleagrls Cuv., Cape, , 



* A. Gunther, " Contribution of the Anatomy of Hatteria (Rkyncliocj- 

 phalus^ Gray." Phil. Trans. Roy. Soc., London, vol. 157, ii., 1867. 



