322 3. IGUANID^ 



Sceloporus yarrowi Coues, Surv. W. looth Merid., Vol. V, 1875, p. 569, 



pi. XXII, figs. 2-2C. 



Sceloporus yarrowii Boulenger, Cat. Lizards Brit. Mus., Vol. II, 1885, 



p. 223; GuNTHER, Biologia Centrali-Americana, Reptiles, 1890, p. 



69; Boulenger, Proc. Zool. Soc. London, 1897, p. 483; Ditmars, 



Reptile Book, 1907, p. 135. 

 Sceloporus fleurolefis Gunther, Biologia Centrali-.Americana, Reptiles 



1890, p. 74, pi. XXXII, fig. B (type locality, Jalisco, Mexico, 



north of the Rio Santiago). 

 Sceloporus torquatus poiiiseltii Cope, Report U. S. Nat. Mus. for 1898, 



1900, p. 350 (part). 



Description. — Head and body considerably depressed. 

 Nostril opening much nearer to end of snout than to orbit. 

 Upper head-shields smooth, moderately large, flat or very 

 slightly convex; interparietal much largest. Frontal usually 

 divided transversely. Parietal, frontoparietal and frontal 

 plates separated from enlarged supraoculars by a series of 

 smooth plates or granules. Superciliaries long, wide and 

 strongly imbricate. Middle subocular very long, narrow 

 and strongly keeled. Rostral plate low, but very wide. 

 Labials long and low. Below lower labials and behind large 

 pentangular symphyseal a series of sublabial plates larger 

 than gulars, separated from infralabials (except first) by 

 one or two series of smaller sublabials. Gulars of moderate 

 size, smooth, imbricate, and usually emarginate posteriorly. 

 Ear-opening large, slightly oblique, with an anterior denticu- 

 lation of smooth, acuminate scales, one of which usually is 

 much wider than the others. Back with equal-sized, weakly 

 keeled, but strongly pointed scales, arranged in nearly paral- 

 lel longitudinal rows. Scales on sides similar to those on 

 back but smaller, more sharply mucronate, and directed 

 obliquely upward. No longitudinal folds, and no transverse 

 fold across throat. Superior surfaces of limbs provided 

 with large, keeled, strongly mucronate scales. Posterior 

 surface of thigh covered with moderate-sized, pointed. 



