154 3. IGUANIDM 



pp. 28, 31, 51, (part); Nelson, Mem. Nat. Acad. Sci., Vol. XVI, 

 1921, pp. 114, lis, 126. 

 Callosaurus ventralis, Stephens, Trans. San Diego Soc. Nat. Hist., Vol. 

 Ill, No. 4, 1921, p. 61. 



Description. — Head rather short and low, with well de- 

 veloped canthus rostralis. Nostrils large, opening on upper 

 surface of snout. Supraocular regions covered with small 

 plates and separated from each other by one or two rows 

 of slightly larger plates. Upper head plates (except inter- 

 parietal) small and irregular, largest on frontal and pre- 

 frontal regions, everywhere smooth and rather flat. Sev- 

 eral subocular plates, middle one very long and strongly 

 keeled. Supcrciliaries rather small, but strongly imbricate. 

 Eyelids bearing a well developed fringe. Supralabials 

 strongly imbricate, and produced laterally so as to form a 

 series of curves when seen from above. Infralabials small, 

 juxtaposed. Below them, several series of flat sublabial 

 plates. Gulars granular and smooth, growing larger and 

 imbricate on posterior fold. Back and sides covered with 

 small flattened granules, which change gradually into 

 much larger smooth ventrals. A dermal fold usually ex- 

 tending along each side between limbs. Tail of moderate 

 length, much flattened, its scales slightly imbricate, and 

 along its edge, pointed. Limbs very long and slender. 

 Ear-opening large, without denticulation. Femoral pores 

 varying from eleven to twenty-four, usually 15 to 18. 



The general color above is grayish, dotted and spotted 

 with white or pale gray, and with indications of dark dor- 

 sal blotches which are most distinct in females and young. 

 The top of the head is rich cream, clouded with dark slaty 

 gray. The upper surfaces of the limbs are crossed by 

 more or less obsolete bands of dark brown or blackish slate. 

 A dark line, bordered above and below with white, runs 

 along the back of the thigh. The upper surface of the 



