CROCODILIANS, LIZARDS, AND SNAKES, 521 



Elgaria snndcauda Baird and Girahd in Stansb. Expefl. Gt. Salt Lake, 1852, p. 



348; U. S. Explor. Exped. (Cb. Wilkes), Ilerp., 1858, p. 210, ])1. xxiii, figs. 1-9. 

 Elgaria grandis Baird and Girakd, Stansb. Exped. Gt. Salt Lake, 1852, p. 176. — 



GiRARD, Wilkes Expl. Exped., 1858, p. 212, pl.xxii, figs. 1-9. 

 Elgaria marginata Hai.lowkll, Proc. Acad. Nat. Sci. Phila., 1852, p. 179; Sit- 



greaves, Expl. Znni and Colo. River, 1853, p. 114, pi. iii ; young specimen. 

 Gerrhonotns uebhii Baird, Proc. Acad. Nat. Sci. Phila., 1858, p. 255; U. S. Mex. 



Bound. Surv. Rept.. 1859, p. 11, pi. xxiv, figs. 1-10. 

 Cevvhouoiiis {Elgaria) grandis O'Shaughnessy, Ann. Mag. Nat. Hist. (4), XII, 



1873, p. 47. 

 Gerrhonotua (Elgaria) seincicaiida O'Shaughnessy, Ann. Mag. Nat. Hist. (4), XII, 



1873, p. 47. 

 Gerrhonotns (Elgaria) formoaus O'Shaughnessy, Ann. Mag. Nat. Hist. (4), XII, 



1873, p. 47. 

 Gerrhonotns (Elgaria) principis O'Shaughnessy, Ann. Mag. Nat. Hist. (4), XII, 



1873, p. 47. 



Two pairs of internasals and two of postnasals, the hinder pair 

 sometimes fused into one. Frontal separatin^f widely tlie postfroutals 

 and internasals. Sni)raorbitals in two series of live and three. Head 

 very broad and swollen behind, where tbe width is more than two-thirds 

 length to ear. Hind feet from knee equal or a little greater than this 

 distance. Tail two and one fourth to two and one-half times the head 

 and body (iu Cat. No. 3102a). 



Dorsal scales in fourteen transverse and forty-seven to fifty longitu- 

 dinal series. Scales all i)rominently carinated, the carina' equidistautj 

 scales on anterior as well as upper face of limbs showing more or less 

 carination, as also the sides of the tail. 



Color above yellowish brown or gray, with a series of ten to fourteen 

 blackish rings, continued quite distinctly across the back, and spotted 

 bcliind with white even in the median region. 



This is a variable species, so much so as to have given rise to a 

 number of synonyms. It was first described from a young specimen 

 by Wiegnumn as G. cwndeus, a name wliich is absolutely erroneous as 

 applied to the species in general. Another young individual gave rise 

 to the synonym G. webJni Baird. 



In this species the body is cylindrical or subquadrate, rather 

 depressed J the belly flattened. There is a decided constriction at 

 the neck; the head as wide as the body, a little broader than high; 

 the width two-thirds the distance from muzzle to ear, which again is 

 two ninths the head and body. The tail is excessively lengthened, two 

 and one-third times the head and body, though frequently much shorter 

 owing to the breaking off and reproduction in a stump of the tail. This 

 is shaped like the body, thcmgh less depressed ; and without the soft 

 skin of the sides, though with a shallow groove. The feet are short 

 and feeble. 



On each side the body is a fold or strip of soft skin paved at inter- 

 vals with small oval scales, with still smaller ones between them, 

 especially on the sides. This begins at tbe ear and extends backward 

 to the root of the tail, the legs being implanted in it. On the sides it 



