6. CROTAPHYTUS 125 



ground the lizard jumped four inches into the air after it. 

 In executing this leap all four feet necessarily left the 

 ground. Once the lizard crouched down on a gray sage- 

 leaf background with which the color of its body blended 

 perfectly. 



"Numbers of the females exhibited the red coloration 

 characteristic of some examples during the breeding season. 

 The first specimen showing this character was secured June 

 8, between Quinn River Crossing and Big Creek Ranch," 

 Nevada. 



Ruthven and Gaige, in northeastern Nevada, found a 

 large female containing eggs July 13. The first young 

 (129 mm. in total length were seen on August 14. Rich- 

 ardson says: "Two females taken at the Pyramid Lake 

 Indian Agency between May 26 and June 1 contained two 

 and four eggs, respectively. One secured at Derby on 

 June 29 carried two well-developed eggs, and another 

 taken at Carson City on July 10 contained large eggs and 

 had assumed the brilliant red-orange breeding colors." 



Regarding this red coloration assumed by the breeding 

 females, which has a curiously superficial appearance, Dr. 

 Merriam writes: "In many lizards, as well known, the 

 male assumes a special coloration during the breeding 

 season. The present species is a notable exception, the male 

 remaining the same, while the female undergoes a remark- 

 able change. The whole under surface and sides of the 

 tail become deep salmon or even salmon red, and the sides 

 of the body assume the same color, either uniformly or in 

 blotches. The red markings on the sides usually begin as 

 spots, which soon unite to form transverse stripes. The 

 central part of the back is not affected by the change, and 

 the dark markings on the sides remain distinct. None were 

 seen in this condition until May 20, when the first red one 

 was found on Pahroc Plain, Nev., but dozens were seen 



