178 3. IGUANIDM 



1898, 1900, p. 286, fig. 30; Stone & Rehn, Proc. Acad. Nat. Sci. 

 Phila., 1903; p. 31; Stone, Proc. Nat. Acad. Sci. Phila., 1903, p. 

 540; Brown, Proc. Acad. Nat. Sci. Phila., 1903, p. 545; Bailey, 

 N. Amer. Fauna, No. 25, 1905, pp. 28, 40; Ditmars, Reptile Book, 



1907, p. 120; Strecker, Proc. Biolog. Soc. Washington, Vol. XXI, 



1908, p. 71; Stone, Proc. Acad. Nat. Sci. Phila., 1911, p. 226; 

 Van Denburgh & Slevin, Proc. Cal. Acad. Sci., Ser. 4, Vol. 3, 

 1913, p. 399; Strecker, Baylor Bulletin, Vol. XVIII, No. 4, 1915, 

 p. 17; Stejneger & Barbour, Check List. N. Amer. Amph. Rept., 

 1917, p. 49. 



Holbrookia afmis Baird & Girard, Proc. Acad. Nat. Sci., Phila., Vol. VI, 

 1852, p. 125 (type locality, San Pedro); Baird, U. S. Mex. 

 Bound. Surv., Vol. II, Rept., 1859, p. 8; Bocourt, Miss. Sci. Mex., 

 Rept., 1874, p. 163. 



Description. — Head rather short and low. Nostrils 

 large, opening on upper surface of snout. Supraocular 

 regions covered, with small plates or granules, and separated 

 from each other by one or two rows of somewhat larger 

 plates. Upper head-plates, except interparietal, small and 

 irregular, largest on frontal and prefrontal regions, every- 

 where smooth and rather flat, often with one or more small 

 pores. Several subocular plates, middle one very long and 

 strongly keeled. Superciliaries rather small, but strongly 

 imbricate. Eyelids with well-developed fringe. Suprala- 

 bials strongly imbricate and produced laterally so as to give 

 snout a rounded outline when seen from above. Infrala- 

 bials small and juxtaposed. Several series of flat subla- 

 bials. Gulars granular and smooth, larger and imbricate 

 on posterior fold. Back and sides covered with scales or 

 granules, largest near middle of back and changing gradu- 

 ally to larger, smooth, imbricate ventrals. A dermal fold 

 usually present along each side between limbs. Tail of 

 moderate length, flattened except distally. Its scales feebly 

 keeled, slightly mucronate, imbricate, except base of tail. 



