LIZARDS. 179 



B. Nostril lateral. Toes simple or fringed. Back crested. 

 Interparietal plate small. 



a. Femoral pores distinct. 



* Throat-pouch lai'ge, compressed. Tail compressed. 



6. Iguana. Scales of back moderate. Throat-pouch toothed in 



front. 



7. Aloponotus. Scales of back very minute. Throat-pouch 



simple in front. 



** Throat rather dilatable^ with a cross fold behind. Middle hind 



toes toothed on the outside. 



f Tail compressed, with uniform keeled scales. 



8. Brachylophus. Head-shields flat. Femoral pores 1-rowed. 



9. Metapoceros. Head-shields flat. Central frontal with a horn. 



Femoral pores 2-r()wed. 



10. Trachycephalus. Head-shields convex. Hinder outer toe 

 short. 



11. Oreocephalus. Head-shields conical, very rugose. The 

 outer hinder toe elongate. 



W Tail ivith rings of spinose scales. 



12. Cyclura. Head-shields small, vidth 2 rows of large shields 

 on the muzzle. Tail compressed. 



13. Ctenosaura. Head and muzzle shields small, uniform. Tail 

 roundish, crested. 



14. Enyaliosaurus. Head and muzzle shields small, unifoi-m. 

 Tail depressed, with 5 longitudinal spinose ridges. 



b. Femoral pores none. 



* Hinder toes fringed on the side, outer icebbed at the base. Throat 



ivith a cross fold behind. 



15. Basiliscus. Head elongate, with an erect crest behind. The 

 back and tail with a fin-like crest. 



16. CoRYTH^oLus. Head elongate, with a low compressed crest 

 behind. Back and tail with a low toothed crest. 



17. Thysanodactylus. Head short, with a low toothed crest, 

 convex behind. Back and tail with a low toothed crest. 



** Toes all slender, simple or slightly serrated on the sides. Outer 

 hinder toes quite free. Head short. 



f Occiput compressed and produced behind. Throat-pouch 



compressed. 



18. Corythophanes. Nape crested. Throat-pouch toothed in front. 



