4 IGUANIDE. 
B. Digits not dilated. 
1, Premaxillary teeth conical. 
a. Infradigital lamella 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 ........ eee ee 7. Corythophanes, p. 101. 
No gular sac; occipital region flat.. 8. Lemanctus, p. 104. 
No gular sac ; toes lobate ........ 9. Basiliscus, p. 106. 
f. Head not produced posteriorly. 
* One or more transverse gular folds, or a very large’ 
occipital (or interparietal) shield, 
+ Sternum without fontanelle. 
+ 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. —_ 
tt Body depressed. 
A dorsal crest ; toes denticulated laterally. 
19. Chalarodon, p. 128. 
No dorsal crest ; toes compressed .. 20. Hoplurus, p. 129. 
No dorsal crest; toes depressed, denticulated laterally. 
17. Pristidactylus, p. 127. 
+r A sternal fontanelle; occipital shield very large. 
+ 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. pies chance dew eds 28. Uraniscodon, p. 178. \ 
tt Caudal scales very large and spinose. 
No fold across the throat ; tail subcylindrical. 
29. Strobilurus, p. 181.——_ 
Two folds across the throat; tail flat. 
30. Urocentron, p. 182. —— 
1 Je, much larger than the eye-opening. 
