148 REPTILES OF THE WORLD 



called the porcupine lizard. Greenish gray above, it is 

 decorated with a broad, black, yellow-bordered collar. 

 Mexico is the home of this stout species. A variety of 

 it known as poinsettii extends into the United States, 

 where it lives in rocky areas of Arizona, New Mexico 

 and southwestern Texas. 



Most widely distributed of the ten species of spiny 

 swifts found in the United States, is the Common 

 Swift; called in the Eastern States the Fence Swift, 

 S. undulatus. The typical form is abundant from the 

 Atlantic to the Pacific Coast; in the East it does not 

 extend north of southern New Jersey; in the West it 

 ranges as far north as Oregon. Its color is grayish, 

 crossed with wavy black bands, these often broken into 

 two series of irregular Vs. This is a small species; a 

 mature example is about five inches long. 



Old fences are much frequented by this species. The 

 lizards scamper along the stiles, or, if approached, dodge 

 over on the side opposite to the observer. In the dry 

 pinelands of the southeastern portion of the United 

 States, there is a swift or two for every fallen tree trunk. 

 To catch a specimen one must exercise considerable in- 

 genuity, as a rush at the creature would cause it to 

 scurry under the tree trunk, there to wriggle its way 

 into the debris, or jump from the log, run to the nearest 

 tree and ascend to a perfectly safe distance to peer 

 saucily downward. As the collector approaches a log 

 on which a swift is basking, the lizard generally dodges 

 over the side, away from view. The spot whence the 

 specimen has disappeared should be noted: for it will 

 usually be found that the lizard has simply danced 

 round the horizontal trunk. Bringing the hand slowly 

 over the log, but keeping the body out of sight as much 

 as possible, the collector should take an instant's glance 



