3 30 3. IGUANID.^ 



Proc. U. S. Nat. Mus., Vol. 48, 1915, p. 418; Van Denburgh & 

 Slevim, Proc. Cal. Acad. Sci., Ser. 4, Vol. 5, No. 4, 191 5, p. loo; 

 Camp, Univ. Cal. Pubis. Zool., Vol. 12, No. 17, 1916, p. 526; Grin- 

 NELL & Camp, Univ. Cal. Pubis. Zool., Vol. 17, No. 10, 1917, p. 

 162; Stejneger & Barbour, Check List N. .Amer. Amph. Rept., 

 1917, p. 55; CowLES, Journ. Entomol. & Zool., Pomona College, 

 Vol. XII, No. 3, 1920, p. 65; Stephens, Trans. San Diego Soc. 

 Nat. Hist., Vol. Ill, No. 4, 1921, p. 62; Van Denburgh & Slevin, 

 Proc. Cal. Acad. Sci., Ser. 4, Vol. XI, 1921, pp. 28, 34, 51. 



Sceloporus clarkii clarkii Cope, Bull. U. S. Nat. Mus., No. I, 1875, p. 

 40 (part); Yarrow, Su'rv. W. looth Merid., Vol. V, 1875, p. 575, 

 (part). 



Sceloporus clarki clarki Coues, Surv. VV. looth Merid., Vol. V, 1875, 

 p. 594 (part); Yarrow, Bull. U. S. Nat. Mus., No. 24, 1883, pp. 

 II, 63 (part). 



Sceloporus splnosus clarkii Boulenger, Cat. Lizards Brit. Mus., Vol. 

 II, 1885, p. 227 (part). 



Sceloforui sfinosus Gunther, Biologia Centrali-.Americana, Reptiles, 

 1890, p. 63, (part). 



Sceloforui clarkii Yarrow & Henshavv, Ann. Report Chief of Engi- 

 neers for 1878, Surv. W. looth Merid., Appendix NN, 1878, p. 223 ■• 

 Stejneger, N. Amer. Fauna, No. 3, 1890, p. no; Cope, Amer 

 Naturalist, Vol. XXX, 1896, p. 1014 (part). Cope, Report U. S' 

 Nat. Mus. for 1898, 1900, p. 358 (part); Ditmars, Reptile Book' 

 1907, p. 128, pi. XLIII, fig. 3 (part). 



Sceloporus spinosus magister Boulenger, Proc. Zool. Soc. London, 1897, 

 p. 496. 



Description. — Head and body little depressed. Nasal 

 opening slightly nearer to end of snout than to orbit. Upper 

 head-plates smooth, often a little convex, and usually 

 slightly imbricate; interparietal largest. Frontal divided 

 transversely. Parietal and (usually) frontoparietal plates 

 rot separated from large supraoculars. Latter very broad, 

 as are also the strongly imbricate superciliaries. Middle 

 subocular very long, narrow and strongly keeled. Rostral 

 plate wider than high. Labials long but very low, inferior 

 larger than superior. Symphyseal large, and followed by 

 several plates larger than gulars and separated from lower 



