98 



GENERAL EVOLUTION. 



Abdominal ribs. 



iGUANIDiE. 



Polychrus. 



Agamid^. 

 * * 



No abdominal ribs. 



Ribs creatly prolon!?ed into a lateral wing. 



* *. Draco. 



Ribs not prolonged. 



Arboreal types, generally compressed. 



A dorsal and caudal fin supported by bony rays. 



Basiliscus (no fern, pores). Lophura (pores). 

 No vertebral fin. 



No femora! pores. 

 Form slender, scales in Calotes. [ 



equal series. Bronchocela. J 



Form elongate ; eyebrows 



elevated, tail compressed. Gonyocephalus. 

 Form stouter, scales less 



regular. Hypsibates. 



Femoral pores. 

 Low crested; small hyoid 



disk. Brachylophus. 



High crested ; large hyoid 



disk. Iguana. 



Tail with spinous whorls. Cyclura. 



Terrestrial types of flattened form. 



Femoral pores. 

 Tail with whorls of spiny 



scales. Hoplocercus. 



. Tail long, simple ; scales 



small. Crotaphytus. 



Tail simple, scales large. Sceloporus. 



No femoral pores ; preanal pores. 



Tail with whorls of spines. * * Stellio. 



Tail simple, not elongate, 



ear open. Proctotretus. Agama. 



Neither femoral nor anal pores. 



Much flattened, tail short, scales irregular. 



Phrynosoma. Moloch. 



I Phrynocephalus. 

 ( Megalochilus. 



Lsemanctus. 



Ophryoessa. 

 Tiaris. 



Diporophora. 



Physignathus. 

 * * 



Uromastix. 



Liolepis. 

 * * 



Ear exposed. 

 Ear concealed. 



(Doliosaurus, s. g.) 



A similar parallel may be drawn between the American Teidse, 

 and the Old World Lacertidae, and in fact between all the families 

 of the Lacertilia Leptoglossa. I have added to these for compari- 

 son two families of the Typhlophthalmi. Each family embraces 

 one or more series, and these exhibit a remarkable similarity in 

 the relative development of the limbs and digits ; among the 

 higher gronps the parallelisms lie in the arrangement — as greater 

 or less separation — of the head shields. The Scincidse are cosmopo- 

 lite ; the Gymnophthalmidae, which have the eyelids of their foe- 

 tus, are Australian ; the Sepsidae, either larval or senile in head 

 shields, are mostly Ethiopian. 



