598 ZOOLOGY— REPTILES AND BATRACHIANS OF ARIZONA. 



Lizanl of the Eastern States (Scelojwnts undulakis) exhibits corresponding 

 chancres in color. 



This species is very abundant in certain rocky places. Like others of 

 the genus, it is difficult to secure without mutilation, on account of its ex- 

 treme agility and the fragility of the tail. Specimens may be best obtained 

 by switching them off the rocks with a light rod drawn rapidly along the 

 surface. 



23. Crotaphytus collaris, [Say) Holbr. 



Agama collaris, Say, Long's Exped. Rocky Mts., ii, 1S23, 252. — Haklan, Med. & Ptays. 

 Res., 1835, 142. 



Crotaphytus collaris, Holer,, N. A. Herp., ii, 1842, 79, pi. 10. — Bd. & GiR., Marcy's 

 Rep. Exp. Bed Kiv., 1853, 222.— Bd., U. S. & Mex. Bound. Surv., ii, pt, 

 ii, 1859, Reptiles, 6.— Id., P. R. R. Rep., x. 1859, Gunuisou's & Beck- 

 witb's Route, Reptiles, 19, pi. 24, figs. la-e. — III., ib., Whipple's Route, 

 Reptiles, 38.— Cope, Proc. Acad. Nat, Sci. Pliila., 1866, 302.— Id., Cheek- 

 List, 1875, 47. 



A long and well known species of striking characters, type of the 

 genus, and of very general distribution in the Southwest. It was observed 

 by me in New Mexico and Arizona at various points from the crossing of the 

 Rio Grande at Los Pinos to the Colorado Chicpiito River, where it was par- 

 ticularly abundant, on dry, sandy soil among fallen timber, in brush-heaps, 

 &c, It was not noted at Fort Whipple, and probably does not occur in the 

 coniferous mountainous portions of the Territory. 



The length of this species, as commonly observed, is eleven or twelve 

 inches. The colors in life, when the animal is in full vigor, are strikingly 

 rich and varied ; they fade noticeably before death when the creatures fret 

 and pine in captivity, and certainly no description taken from alcoholic 

 specimens, even comparatively fresh, conveys an accurate idea of the rich- 

 ness of the tints. The throat is loose and dilatable, and the animal has a 

 habit of puffing it out when hissing under irritation or in anger. 



This lizard is one of the more ag'ile species of its group, though not so 

 remarkably swift-footed as some of the Cnemidophori, and is difficult to 

 capture alive without injury. It is one of the boldest, fiercest, and most 

 irascible of its kind; those that I kept in confinement proved entirely un- 

 tamable. They not only defended themselves with spirit and vigor by 



