The Swifts 



The species somewhat resembles the common swift (5. 

 undulatus), but differs in reaching a third larger size, having 

 proportionately smaller and smoother scales and much longer 

 limbs. The specimen photographed was remarkable in having 

 two tails. 



Dimensions. Total Length 6j inches. 



Length of Tail 3} 



Width of Head I " 



(Not fully grown) 



Distribution. The Great Basin and the mountain ranges 

 of the Pacific region from Oregon to San Diego County, Cali- 

 fornia, inclusive of both. 



Habits. Mr. D. D. Streeter informs me that he observed 

 many specimens of this lizard on the ground, in rocky districts. 

 They rushed away with great speed when alarmed, making for 

 the clefts under shelving rocks where they invariably defied 

 capture. 



Van Denburgh's Swift, Sceloporusvandenburgianus, (Cope), 

 grows to a length of only five inches. The scales are proportion- 

 ately small. 



Dark green above.with faint traces of a pale band on each side, 

 and obscure, darker cross-bands on the back. The greater por- 

 tion of the under surface of the male is blue. 



Distribution. This seems to be a rare swift and confined 

 to southern California. 



The Yellow-striped Swift, Sceloporus undulatus, variety 

 consobrinus, (Baird & Girard). A variety of the common swift 

 and abundant in many portions of the Western States and in 

 northern Mexico. The very distinct stripes, of a pale hue, on 

 the sides, render it rather characteristic. The scales are small 

 and not heavily keeled, although their spiny tips are rather 

 bristling. It represents one of the smaller species. 



The commonest phase of ground colour is greenish-yellow. 

 On each side of the back are two very distinct and narrow yel- 

 low stripes the upper the most vivid, covering a width of two 

 and a half rows of scales and separated from its fellow by about 

 eight scale rows. On many specimens there is a dusky band 

 between the stripes, on the sides. There are usually but slight 

 indkations of cross-markings and these are very fine. 



