NO. 3545 LIZARDS — PETERS 7 



24. A fold in front of shoulder 25 



No fold in front of shoulder Ophryoessoides 



25. Upper head scales keeled Proctotretus 



Upper head scales smooth Stenocercus 



26. Femoral pores absent 28 



Femoral pores present 27 



27. Ventrals large, square, in transverse and longitudinal rows and distinct from 



very small, granular dorsals Ameiva 



Ventrals not as above Polychrus 



28. A transverse gular fold, complete across throat 29 



No complete gular fold, although a fold in front of shoulder may extend part 



way onto throat 63 



29. Dorsals keeled and imbricate Tropidurus {torquatus only) 



Dorsals smooth and granular Callopistes 



30. Body scales not semicircular, not very imbricate (although sometimes they are 



arranged in 1 6 or fewer rows) ; lack bony plates underlying the scales . .31 



Body scales semicircular, usually smooth or slightly keeled and striated (fig. 



3a), and very imbricate, with underlying bony plates (fig. 3Zi) . . . . 60 



Bony Plate 



Posterior End 

 b 



Figure 3. — Body scales of Diploglossus monotropis: a, dorsal view; b, cross section. 



31 . Dorsal scales heterogeneous; large keeled scales mixed in with smaller granular 



ones 32 



Dorsal scales homogeneous 34 



32. Males with 10 or fewer femoral pores; inner ventrals at least slightly 



keeled 33 



Males with 12 or more femoral pores; inner ventrals smooth . . . Neusticurus 



33. Nostril in suture between two nasals; ventrals small, elongate, subquadrangular; 



double collar fold Dracaena* 



Nostril in single nasal; ventrals large, squarish; single collar fold . Echinosaura 



34. Dorsal scales usually granular, always much smaller than ventrals .... 35 

 Dorsal scales as large as, or only slightly smaller than, ventrals, not gran- 

 ular 41 



35. More than 20 rows of ventral scales 36 



Six to 16 rows of ventral scales 37 



36. Tail strongly bicarinate dorsally Crocodilurus* 



Tail rounded, no raised ridges dorsally Tupinambis 



