The Swifts 



the photo of an adult specimen upon a man's hand. The form 

 is stout and heavy, the tail short and blunt, while the scales 

 are exceedingly coarse, with needle-like bristling points, a char- 

 acter as pronounced on the tail as the formation of the spinous 

 stalks of many plants. When the scales are examined individu- 

 ally, they appear like feathers being sharply serrated along 

 their edges. 



The colouration of the body is dull olive, brown or gray, 

 with indistinct and wavy cross-bands on the back, at a con- 

 siderable distance apart. Around the neck is a broad, jet-black 

 collar, bordered on either side with yellow. The chin of male 

 specimens is blue and there is a bluish patch on each side of the 

 abdomen. From the other species of swifts occuring within 

 the United States and showing traces of a black collar, this 

 lizard may be told by the collar being complete above. 



Dimensions. Total Length 9^ inches. 



Length of Tail 4^ 



Diameter of Tail, at base f 



Width of Body if 



Width of Head .. ij 



Distribution. Southern Arizona, New Mexico, southwest- 

 ern Texas and northern Mexico. Dwells principally in rocky 

 places. 



The Sage-brush Swift, Scelopoms.graciosus,($aird &Girard), 

 differs from the preceding not only in its considerably smaller 

 size, but in colouration. The scalation of the head is quite 

 similar, but the scales of the body are proportionately small. 

 The ground colour is brown or olive. On each side are two dis- 

 tinct, yellow stripes, these enclosing a dusky band. On each 

 side of the back is a series of dark and narrow crescents. Be- 

 tween the stripes on the sides, is another series, of similar size. 

 All of these crescents are bordered at their rear with yellow, 

 this hue greatly accentuating their outline. In front of the 

 forelimb and almost in contact with its base, is a round, black 

 spot. The abdomen of male specimens is marked with two 

 blue blotches and the chin is tinted with the same colour. 



Resembles the striped swift (S. scalaris), but may be at 

 once separated by the scale formula of the head and the smooth- 

 ness of the larger head plates. 



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