PROCEEDINGS OF THE NATIONAL MUSEUM 



12. 



13. 



14. 



15. 



16. 



A strong transverse gular fold 13 



No transverse gular fold Stenocercus 



Dorsal crest present Enyalioides 



Dorsal crest absent Morunasaurus 



Scales below ear subequal in size 15 



A large, round, flat scale belov/ ear Iguana 



Head produced posteriorly forming a vertical fin (in female, especially young 



ones, somiCtimes very inconspicuous) 16 



Head not produced posteriorly 17 



Toes of hindfoot with fringe of flat scales (fig. 2a) Basiliscus 



Toes of hindfoot without fringe (fig. 2b) Corythophanes* 



Figure 2.— Toe of hindfoot: a, Basiliscus; b, Corythophanes. Occipital: c, Leiocef 

 species; d, Tropidurus holotropis. 



17. Toes not dilated but quite cylindrical or compressed 18 



Toes dilated and flattened Anolis 



18. A raised dorsal crest or slightly enlarged row of vertebral scales 19 



Dorsal crest absent •^" 



19. No femoral pores 20 



Femoral pores present Enyalioides 



20. A transverse gular fold extending completely across throat 21 



No transverse gular fold extending completely across throat 23 



21. Infradigital lamellae distinctly keeled 22 



Infradigital lamellae smooth or vaguely keeled Enyalius 



22. Anterior maxillary teeth longest ■f^^'^'^ 



Maxillary teeth subequal Tropidurus 



23. Occipital small (fig. 2c) 24 



Occipital gready enlarged (fig. 2d) Tropidurus 



2 When this key is used for generic identification of non-Ecuadorian forms, Uranoscodon 

 will key to Plica, since they are identical in external characters used. Uranoscodon lacks 

 a sternal fontanelle, Plica has one. It is unlikely that Uranoscodon occurs in Ecuador. 



