4 IGUANID-E. 



B. Digits not dilated. 



1. Praem axillary teeth conical. 



a. Infradigital lamellae distinctly keeled. 



a. Posterior part of head more or less produced. 



A gular sac ; head with two ridges uniting posteriorly into an ele- 

 vated bony crest 7. Corythophaiies, p. 101. 



No gular sac; occipital region flat. . 8. Lsemanctus, p. 104. 



No gular sac ; toes lobate 9. Basiliscus, p. lOG. 



/3. Head not produced posteriorly, 



* One or more transverse gular folds, or a very large ^ 

 occipital (or interparietal) shield. 



t Sternum without fontanelle. 



X Body more or less compressed ; a dorsal crest. 



No abdominal ribs ; no gular sac ; no femoral pores. 



10. Ophryoessa, p. 111. 



Abdominal ribs ; male with a more or less developed gular sac and 

 usually a few femoral pores .... 11. Enyalioides, p. 112. 



XX Body depressed. 



A dorsal crest ; toes denticulated laterally. 



19. Caalarodon, p. 128, 



No dorsal crest ; toes com'^jressed . . 20. Hoplurus, p. 129. 



No dorsal crest ; toes depressed, denticulated laterally. 



17. Pristidactylus, p. 127. 



ft A sternal fontanelle ; occipital shield very large. 



X Caudal scales small or moderately large. 



Digits straight; no canine-like teeth 27. Tropidurus, p. 171. 



Digits strongly bent at the articulations ; anterior maxillary teeth 

 longest 28. Uraniscodon, p. 178. 



XX Caudal scales very large and spinose. 



No fold across the throat ; tail subcylindrical. 



29. Strohilurus, p. 181. 



Two folds across the throat ; tail flat. 



30. XJrocentron, p. 182. 



^ /. c. much larger than the eye-opening. 



