XII AGAMIDAE 5 1 5 



(iroup I. Zonuridac and Aiiguiilai' assuiin! a central position, witli Iguanidae 

 and Agamidae as two jjarallel families of highest development. 

 Aniollidae as the most degraded forms. Helodermatidae and 

 Lanthanotidae as rather primitive and solitary survivals. 



Agamidae Iguanidae 



Xenosauridae 



I 

 Zonuridae — Anguidae — Helodermatidae, 



Aniellidae. 

 Grou]! ir. Xantusiidae — Tejidae — Aiuphisbaenidae. 

 GrdU]) III. Scincidae — Geri'hosauridae — Lacertidae. — Here also Anelytro- 



pidac and ])('rlia]is also Dihaniidae as degraded Scincoids. • 

 Group 1\'. N'aranidae, which are in many resjjects the most highly develo2)ed 

 of all. 

 Pygopodidae are of obscure relalionshiji. 



Fam. 1. Agamidae. — Acrodont, Old-World Lizards, with a 

 l)road and short tongue. The teeth are usually difierentiated 



^H agamidae:. 

 Fig. 122. — Map showing the distribution of tlie Agamidae. 



into incisors, canines, and molars. The orbit is closed posteriorly ; 

 the temporal fossa is bridged over by an arch whicli is formed 

 cliiefly by the squamosal and the well-developed jugal ; the post- 

 orbital mostly remaining small, and the postfrontal and supra- 

 temporal bones lieing either absent or not present as separate 

 elements. The limbs are well developed. The eye, provided 

 with complete eyelids, is distinctly small and has a round pupil. 

 The skin is devoid of osteoderms, although large and numerous 

 spines are often present, especially on the head and on the tail. 

 The Agamidae, of which about two hundred species, arranged 



