CROCODILIANS, LIZARDS, AND SNAKES. 



275 



those of the desert that it can hardly be seen. The basal half of its tail is trans- 

 versely barred nnderneath, and the bars are broad and distinct, suggesting the name 

 here applied to the species in lieu of a better one. During the breeding season the 

 males develop a conspicuous j)atch of metallic greenish-blue on the sides of the 

 body and have the power of inflating a pinkish sac under the chin. 



The attitude of this lizard when at rest differs from that of most others, in that 

 the knees and elbows stand out at right angles from the body, and are elevated to 

 such a degree that they nearly reach the plane of the back. Like many other spe- 



cies, it has an odd habit of performing a singular gynmastic exercise, consisting in 

 rapidly dropping and elevating the body with the knees held stiff at right angles to 

 the trunk. 



This species feeds on insects and the blossoms and leaves of plants in about equal 

 proportion ; at h)ast such was the case in the large number whose stomachs were 

 examined. 



The gridiron-tailed lizard is common throughout the Mohave Desert proper, but 

 docs not reach the extreme western end of the desert in Antelope \alley. which, 

 owing to its greater altitude, passes out of the Lower Sonoran zone. It was last 



